Migrating from Cumulus 1 to MX

From Cumulus Wiki


This page was inspired by this update from Cumulus 1 forum topic. That post was made in January 2020, and therefore the bulk of the text on this page relates to Version 3.3.0, which was the MX release that was in use at the time.

Crystal Clear info.png This page was last partially updated for the MX release in July 2020; that is no longer latest!

Appeal to contributors: Please work through all MX release announcements and work out all the many updates needed for this page, it may even need a redesign for more recent releases!

You might want to read the related page at My_migration_from_C1_to_MX which describes how this worked in practice for release version 3.4.5 (build 3069).

Should I migrate to MX or not?

The legacy Cumulus will never be updated, and as more people migrate to MX there will be fewer people to help you if the legacy cumulus software gives you a problem. MX has a major advantage it runs on more devices, and for example a Raspberry Pi computer is far cheaper to leave on all the time to run MX (knowing it will never be rebooted by Windows updates). The current developer of MX offers support, and other people are also gaining expertise, so if you have a problem you will get help.

Of course MX started with very little of the functionality that the original Cumulus offered, but over time MX has gained more and more functionality. Features in the original Cumulus have been gradually added to MX, but also MX offers a lot that is not in the original Cumulus. See Compare C1and MX page for more on this. Unfortunately, there is no list anywhere of all features in Cumulus 1. About_Cumulus does not cover all features. Nor is there a list of features still to be introduced into MX. Therefore it is hard to help you understand whether functionality changes between the flavours will suit you.

There are Cumulus users who tried MX, then have migrated back (from MX) to the legacy product; either on a temporary basis (to use a missing feature before they return to MX) or in a very few cases decided to stay with Cumulus 1 (because they prefer it). It is worth noting here that the legacy Cumulus is a stable product with very few bugs, but MX is constantly being developed and thus likely to contain bugs (these obviously vary depending on release as some are fixed and others appear). To put this in context, MX now has a huge amount of functionality and it is difficult for the developer to test all the different features.

Cumulus 1 creates a special log containing just temperature and humidity values, this is NOT available in MX.

Although from version 1.7.5 onwards the original Cumulus counts air frosts and gale days, this feature is not in MX.

The This Period screen that is a popular feature of the original Cumulus software as it tabulates data simply, is not available in MX.

Migrating from original Cumulus to beta MX

The beta builds (version 3.0.0) of MX were designed to make it easy to migrate. This section is based on Steve Loft's wording taken from the support forum with minimal alteration for its new context.

You can move between [Cumulus flavours] fairly easily, but you should really read all the guidance.

  • In particular if you use decimal commas with Cumulus 1, then you MIGHT have issues when MX tries to read existing log files.
  • [For separator characters in dates and lists] whilst Cumulus 1 only takes settings from the control panel in Windows,
    • MX running in a Windows environment, takes settings from the locale you specify in a parameter when starting MX, or the Control Panel in Windows,
    • MX running in a non-windows environment takes settings from the locale you specify in a parameter when starting MX, or the default locale in your Mono installation
    • MX [may] take some [settings from] interaction between the two [the specified locale and the default locale], and MX may struggle to read file [lines] created by Cumulus 1 if the MX locale is not precisely same as settings when that file [line was] created.

While MX was in beta, there was limited documentation about what features were included and why, there was some fault reporting and a tracking list that showed when some of those issues were fixed, also initially the documentation on how MX had implemented features it did have was very sparse. The lack of a list of features in Cumulus 1, meant it remains difficult to track which Cumulus 1 features are or are not implemented in MX. Steve Loft said parts of MX were simply machine code level copies of parts of Cumulus 1 functionality, and parts were trying to offer better functionality, but he never said what was included in these two categories.

There was a list of enhancements requested by users for Cumulus 1, but that list was deleted before work on MX started. Despite that, it does seem that some features that were on the now lost list of enhancements for Cumulus 1 that never got implemented in Cumulus 1, have been implemented in MX, although again there is no definitive documentation.

How to install MX

The basic instructions for installing MX:

  1. Download the MX distribution (from Software for latest version or from https://github.com/cumulusmx/CumulusMX/releases if you want an earlier release version)
  2. Unzip into the location where you are going to install MX.

Alternatively, follow instructions at Raspberry Pi Image which describes a simpler way to install MX (assuming you have another device linked to your RPi to do downloads and micro-SD card preparation).

Migrating from legacy Cumulus to a recent build of MX

The text that follows mostly relates to version 3.3.0, it probably needs to be updated, as later releases of MX have massively changed. The newer releases are more fussy about formats used in files, and migration from the legacy Cumulus software is harder

If you want to continue using the same weather station, and you are not moving to a different home, you will want to maintain the data you collected using Cumulus 1 in your MX installation. This is what is meant by migration, and is the subject of the rest of this article.

'Engine' and 'Admin Interface' for MX

When you run the original Cumulus software it displays a screen (see Cumulus_Screenshots#Main_Screen, and from there you navigate to other screens to view data or change settings.

MX is different, it consists of a stand-alone 'engine' which performs the reading and logging of data, uploading to a web site etc. This 'engine' is a command-line/terminal/console application which has no user interface. It does write diagnostic information to a diagnostic log, but many people run MX on a device that has no monitor and so the terminal output (if any) is not monitored.

When you successfully start MX, the engine is running, and it continues, until it is terminated by control C (or its equivalent in a Mac environment).

The separate admin interface is provided by virtue of the engine acting as a web server. You can view the admin interface by typing the URL of the built-in web server into your browser, either on the same machine, or on a separate machine sharing the same local network. If you install MX on Microsoft Windows, then a few extra one-off steps are needed to allow this web server functionality:

  1. Windows Defender has to be told to allow all for Cumulus MX.
  2. Typically for other security packages, select "CumulusMX.exe" then right click and select "Change File Rating to Trusted"
  3. In any "Firewall" package, add port 8998 as one that was permitted.
  4. Using "command prompt as administrator" type netsh http add urlacl url=http:// user=\users, the response "URL reservation successfully added" means it worked. This command is apparently to allow all users to bind to port 8998 (i.e. that used for the Cumulus interface). This also means you don't have to run the engine (CumulusMX.exe) in an administrator user, nor select "Run as administrator" from right click menu on the shortcut, nor set the properties for any shortcut to run in any special way.
The default URL if the browser is on the same machine as MX is http://localhost:8998/. 

If you are using the browser on a different device on your local network to the device running MX, you cannot use that local host shortcut. Instead you specify a IPv4 address, that is listed in your router (might be called a hub) for the device running MX, this IPv4 address will look like '192.168.y.z' (where y and z are numbers that vary between implementations). For example you might acces the admin interface by typing "".

Equally, if "localhost" is already in use for another web server (that you already run on your device), unless you can differentiate purely by port number you may need to use the correct IPv4 address as above, even on the same device.

For security reasons, the admin interface should not be accessible via the public internet.

Configuration file

MX's Cumulus.ini has different content to the legacy cumulus.ini.

Cumulus 1 can recognise, in some circumstances, "cumulus1.ini", and other variants, not just "Cumulus.ini". MX only recognises "Cumulus.ini".

The old approach for migration, was to copy across your existing file, and let MX ignore all the parameters that do not apply to it. To add the parameters that MX does need, you would then go to the MX_Administrative_Interface#Changing_Settings pages and work steadily through ALL the options. For any parameters that were not set by the admin interface (and there were many "read-only" parameters in early releases of MX), one assumed these also existed in Cumulus 1 and so were already in your file.

At releases like 3.3.0 and 3.6.0, amongst others, there were changes to "read-only" parameters for MX. These could not be adjusted through the admin interface, and needed to be entered manually. To keep this page simple, it cannot list the "read-only" parameters that you might need to add for migrating to earlier releases.

It appears that from release 3.10.1, all settings are now initialised via the admin interface (and none are "read-only"), so if you are using that release or later, it may be better to ignore your Cumulus 1 configuration file, and to let MX create a configuration file with just the parameters it needs using the various [MX_Administrative_Interface#Changing_Settings|settings pages in the admin interface]]. That will ensure you don't get muddled by parameters used for Cumulus 1 (but not for MX); and you do have all the parameters you do need, set correctly.

Start date

When you first run any Cumulus software (whatever flavour) a parameter is added to the configuration file that documents the date Cumulus was first used.

For Cumulus 1, this parameter appeared in two places on the example web template for all-time records, but was otherwise ignored. Thus if you decided to import into your data logs readings from before you first ran Cumulus, the legacy software would be able to find those earlier records.

CumulusMX.exe uses this parameter to determine the first standard log file to start reading from, it will ignore any log files for earlier dates. Thus if you were to migrate your Cumulus 1 configuration file into MX, you should check the "StartDate=" line in the '[Station]' section is correct for your earliest data before you let MX read this configuration file for first time. If you need to make any edit, ensure you stick to exactly the same date format.

From release 3.10.1, MX allows you to edit this start date within the admin interface. It is "hidden" as an "advanced" setting, with a strict danger warning, but it is there!

Uploading to web site

Many settings have changed in this area for MX, and they vary depending on which release you are installing. No attempt is made to explain further here.

Station connections

If your weather station used a port to connect to Cumulus 1, that port was set on the settings screen as a number and stored in Cumulus.ini_(Cumulus_1) in the station section as a parameter in the format Port=n.

In Cumulus MX, as it runs on various operating systems, the port is specified using text (instead of a number), again you select it within settings, on Station settings page, but within Cumulus.ini in the station section the parameter is in the format Comport=tttttttt.

If your old parameter had a value of 3, and you are still using Windows, the new setting would have value of COM3.

A typical parameter value for other devices might be "/dev/ttyUSB0".

RG11 Rain gauge

If you use a RG11 rain gauge:

  • Replace: RG11port=n and RG11port2 =n (Cumulus 1) where n is a number, by RG11portName=xxxx and RG11portName2=yyyy (Cumulus MX on Windows) where the value is a string with values as per previous paragraph depending on device on which Cumulus MX is running.

From release 3.10.1, there appear to be other new parameters, not yet documented.


This is another configuration file, but it is an optional one. If you have not created a strings.ini file in your (leagacy) Cumulus top level folder, then you have no file to move to your MX installation, and you should skip the rest of this sub-section.

The contents of the samplestring.ini file you get in your MX release distribution varies depending on the release you have downloaded. Check your existing strings.ini file against the samplestring.ini file in the MX distribution you have. If the attribute names (left hand side of the equals sign) match for the parameters you selected to include in your strings.ini, then you can reuse your existing file. If your file includes attributes that are no longer in the MX samplesting.ini file, then you will need to edit your strings.ini file that is placed in the folder containing CumulusMX.exe.

Please remember that the Microsoft Windows Operating System is case insensitive for file names, if you install MX on a Windows PC, then "Strings.ini", "STRINGS.INI", and "strings.ini" are all treated as the same file by MX. If you install MX on another operating system, then the file system is case sensitive, in this case MX will only recognise "strings.ini".

For those of you who are more technical:

  • Note that files created in Microsoft's Windows Operating System use two characters (carriage return and line feed) to end each line, while all other operating systems use a single character (line feed in most Unix derived systems like all Linux variants including Raspberry Pi Operating System). Apple Mac are again different in using just Carriage Return.
  • This should not cause any problems for your "strings.ini" file as MX does not care if there appear to be some extra blank lines (because the carriage return may be treated as end one line and the line feed as ending a separate blank line on non-Windows devices).

NOAA style reports

The generation of reports is an optional feature, if you have never used it your (legacy) Cumulus Reports folder will be empty, then you have no files to move to your MX installation, and you should skip the rest of this sub-section.

Please see Reports_folder for full information. Cumulus software creates reports, it does not edit existing reports, so migration is simple. Just copy the contents of the Reports folder in your original Cumulus installation into the folder in the new installation.

For those of you who are more technical:

  • files created in Microsoft's Windows Operating System use two characters (carriage return and line feed) to end each line, while all other operating systems use a single character (line feed in most Unix derived systems). Apple Mac are again different in using just Carriage Return. This should not cause any problems.
  • files can be encoded (how individual characters are represented by binary codes) in different ways. There is more about encoding at Reports_folder#Encoding, the relevance here is that if your MX settings and Cumulus 1 settings use different encodings you may find some characters (e.g. degree symbol) do not appear correctly when viewing some of your reports.

"data" folder

The contents of your Cumulus 1 data folder (log files ending with extension .ini or .txt) can NORMALLY be read by MX (but see points listed below).

However, if you are not running MX on a Microsoft Windows computer, ideally you should change the characters appearing at the end of every line in any file you move from Cumulus 1. To do this, run it through an editor designed for programmers. Various editors are available but "Notepad ++" is one that is popular on Windows, but can run on other operating systems. In its Edit menu, choose EOL conversion. Do remember that with Cumulus 1 on Windows, each line in every file ends with both carriage return and line feed. If you are moving to MX on a Mac, each line should end with just a Carriage Return. For all Unix-based operating systems (Linux, Raspberry Pi OS, and other variants), each line should end with just a Line Feed.

I say ideally, because although Microsoft is fussy, and determined to be different, most other operating systems can tolerate different line terminators. If you use PHP Hypertest Pre-processor anywhere on your installation, you will discover that is written for "Line-feed" as line terminator and any "carriage return" in your files may mess up the content unless you code in a "trim" to remove it. Hopefully, if you use PHP, you are technical enough to realise you may need to edit the code depending on which device it is being run on!

Weather Diary

As explained on weather diary page, the Cumulus 1 weather diary uses a different file to MX, and indeed takes a very different model for how to store the information.

Therefore don't copy Log.xml file into the data folder of your MX installation. You will need to manually use the admin interface Edit menu to access the new diary and add your previous entries one by one.

Please note the editing interface has been changed from release 3.10.1, but the page linked to above may not have been updated. A major change in the upgrade relates to handling of time-zones.

Please also note that the Cumulus 1 weather diary permitted multiple entries to be stored for an individual day, but the MX implementation only permits a single entry per day. Also the configuration file defines a time when the entries stop applying that may not match the rollover time for other weather measurements.


date format issue

Cumulus 1 allows the date that appears in the first field of each line to use any character (except space) to separate the day of the month, from the month, and from the last two digits of the year. Consequently "29/03/88", "29-03-88", and "29.03.88" are all acceptable in the legacy software (and indeed in some early MX releases).

For MX (from release 3.5.4 onwards), the date separator specified for the locale when you run MX must be used in all lines of this file.

  • See MX_on_Windows_OS#Parameter_for_changing_Locale for how to specify locale if you are running on Microsoft Windows (by default the locale settings are taken from the standard Windows settings application or Control Panel).
  • If you are running MX in a Linux operating system, the locale parameter can be used, but the default locale is determined by the mono-complete package, and that in turn depends on your device settings.

So when you migrate "dayfile.txt", run it through an editor designed for programmers. Various editors are available but "Notepad ++" is one that is popular on Windows. That editor has a "Search" menu, with a Replace... option within it. In that option, there is a "Find what" box, a "Replace with" box, and a "Regular expression" selection.

Suppose your latest lines use either "." or "-" as separator, and that is what MX expects, but you have some older lines using "/" as date separator. Since you know "/" does not appear anywhere but in the dates with an older format, putting "/" in find what box and either "-" or "." (as required) in replace with box will sort you out after you hit "Replace all".

It is all a bit technical, if MX expects "/", but you have "-" in some older lines. The complication comes because "-" may be used in value fields too, so you need to find a way of specifying a minus with two digits before it and two digits after it. For this correction you need to select Regular expression and then set Find what to "^([\d]{2})-([\d]{2})-" and Replace with to "$1/$2/". Please check this, as this was copied from a forum post by Mark Crossley and I have not verified it.

time-stamp format issue

The file contains time-stamps following any value that represents a highest or lowest in the day. These must be expressed as hour and minute, and normally a colon (":") is used as a separator, but again the legacy Cumulus does not actually insist on that while MX does insist that are time-stamps are in "HH:mm" format.

value format issues=

If you moved your Cumulus 1 installation from one windows pc to another, it is just possible that you might have a mix of "decimal comma" and "decimal point" in your values, or you might have changed the field separator (normally ";" or ","). Again, these must be consistent in all lines for mX, and must match what is defined in the locale used.

other .txt files

These should migrate without any problems. You will find that MX creates at least one file that was not in the older Cumulus (monthlyalltimelog.txt).

the .ini files

When Steve Loft designed his original Cumulus (1), he had no experience to draw upon as to the best way to treat items like dates. He wrote the software originally just for his own benefit and did not need to worry about time zones. Subsequently as he enhanced his software to make it usable by others, he faced many issues on how to cope with different time zones, and different weather stations having different sensors. In Cumulus 1, he basically focussed on compatibility by keeping to his original design for the data log files (both those ending in .ini and those ending in .txt, and only adding extra fields to the end.

When Steve Loft took a new look at the data log files for Cumulus 2, he started with a new design, the principal change was that he decided to use UTC for all fields in them that reference dates and times. Steve struggled with Cumulus 2 largely because he was (at that time) not familiar with the C# language he was later to use for MX. It is fair to say that using UTC was also a major factor in his failure to get Cumulus 2 to provide the functionality he had offered in the original Cumulus.

When Steve Loft designed Cumulus MX, he was able to learn from his experiences with both Cumulus 1 and Cumulus 2, and he decided to use dates to an ISO specification (ISO 8601 Data elements and interchange formats – Information interchange – Representation of dates and times), but in the local time zone of the particular user, and therefore log files are not backwards compatible. However those MX beta builds were designed to be forward compatible in that all date formats used by Cumulus 1 could be read, although MX would when rewriting any date change them to the new format.

For the .ini files, Steve Loft did make one change in his beta MX, all values now had to use decimal points in these files, and decimal commas were no longer valid. Thus to migrate to earlier MX releases, if you had used decimal commas, you needed to edit each ".ini" file and change those commas to full stops. Equally, if you had any times not using a ":" as separator, this had to be rectified.

Apart from that, in all versions from 3.0.0 to 3.5.y, there was forward compatibility, and MX could read any file created by the original (legacy) software. MX releases from version 3.0.0 to 3.5.4 can read all the date/time entries in any file whether in the Cumulus 1 format or in the MX format. MX will change any dates to the ISO format only when it needs to update that particular date/time. Consequently, within a single file both formats will co-exist, you may see lines using Cumulus 1 format for the extremes that have existed for a while, and Cumulus MX format for any new extremes.

It appears that releases at versions 3.6.x onwards have become more fussy about existing content in these files due to changes in the source code. However, the developer has not documented whether files from Cumulus 1 can still be read, forward compatibility has only been guaranteed with earlier MX releases. That said, some people are successfully migrating from Cumulus 1 to the newer MX releases, so it works for at least some old files.

General points

File names

Note that if you run MX on a UNIX based operating system (e.g. Linux or Raspberry Pi OS) all file names are case-sensitive, please read documentation to see where capital letters are required in those file names. Be aware that wiki pages change first letter to a capital even when a file that must be all lower-case is being described.

web server

Steve Loft's Cumulus 1 came with a set of example template files (designed by Beth Loft) that could generate web pages to upload to your web server. It also produced a set of images representing standard graphs that could be uploaded to your web server and shown on the default "trends.htm" page, a set of images representing wind speed and direction that could be shown on the default "gauges.htm" page, and a moon image that was shown on one web page. Early MX releases included a replacement set of template files that could generate web pages that (apart from trends.htm and gauges.htm) seemed similar to the legacy pages. However, the earliest release did not generate any images at all, the generation of a moon image was added from release 3.5.0 (build 3071) onwards.

Mark Crossley's Steel Series is used for the MX gauges page, replacing the Cumulus 1 gauges that were based onWeb Dashboard Components for FreeWX and FreeWX-Wi (no longer available) and mixed images generated by Cumulus with plots drawn using JavaScript routines (before "Canvas" functionality).

MX beta introduced use of a set of .json files to convey the data for drawing charts to your web server, and in release 3.10.1 further .json files were added to support default web pages on your web server. The "legacy web pages" were also available in that release modified to use use the new .json files (instead of web templates), but preserving the same look as Beth Loft's web pages.

Whatever release of MX you are installing, the files needed for your web server are in "CumulusMX/webfiles" and its sub-folders. The files that will be automatically uploaded to your web server are created in "CumulusMX/web" folder, depending on the release you are installing, which files are generated and which are uploaded will be determined by settings, later releases in general giving you more control over these files than earlier releases. You can't control the content of the various files, but from 3.10.1 you can individually select which are generated and which are uploaded.

From release 3.10.1, the new default web pages have a totally new look (designed by Neil Thomas), and include responsive code allowing them to look better on wide screens and on narrow screens (such as those on smart mobile phones).


The settings in Cumulus 1 and MX work differently, for Cumulus 1 you choose to save changes by clicking OK, for MX changes are only saved when you click a Save button if one is provided. If there is no Save button anywhere on the screen (as in Extra Web Files) then the setting is saved when you move to next field/line.

Library software

Any non-technical person can skip this sub-section!

  • If you have been using Cumulus 1, and you decided to customise your web site:
    • you may already be using one or more of highcharts, jQuery, bootstrap, and other library software
    • and you may have selected to load latest versions for maximum functionality.
  • You might be enhancing what is provided with Cumulus 1,
  • or you might use your web site for other purposes (not just Cumulus).
  • If so, you may find some Cumulus MX web pages do not work correctly.
    • This is because Cumulus MX uses obsolete versions of library software and the way it is coded means MX is not compatible with current versions.
    • For Cumulus MX to work you need to ensure the versions of such software loaded for your web pages, are not used by your browser when viewing MX admin interface or MX web pages.
  • Equally, ensure that the versions of library software loaded by MX, do not stay loaded when you wish to view any of your web pages that require later versions of these libraries, as your desired functionality might be limited by the library versions MX uses!

Three approaches to installing MX

  1. Install MX OVER your Cumulus 1 installation (this only works if you want to run MX on same PC as you have been running Cumulus 1)
    • This means that all your existing files will be available to MX
    • This is simplest approach for those who want a simple install
    • You may need to edit a few files, please see references to files that might need editing later
    • Because you have Cumulus 1 and MX executables in same location, you would expect it is easy to run either, but as already explained some files can not be read by Cumulus 1 after MX has changed their content
  2. Take a copy of your Cumulus 1 installation and store that copy where you can use it if you want to return to Cumulus 1
    • In original Cumulus 1 location, delete Cumulus.exe (or whatever your Cumulus 1 executable was called)
    • Now follow the instructions for first approach, installing MX over the existing files (but ignore the point about running both executables)
  3. Install MX in a NEW location (this might be on your PC that was running Cumulus 1 or onto another device such as a Pi)
    • This approach requires you to manually copy various files from old folders to new location
    • MX requires all files from "data" and "Reports" folder created by Cumulus 1.
    • You also need "strings.ini" (if you use that), and "Cumulus.ini_(Cumulus_1)", plus any other tailoring set-up files, batch processes etc. you might use.
    • This approach is generally easier if you want to be able to go back to running Cumulus 1


Unzip the MX download (from Software for latest version or from https://github.com/cumulusmx/CumulusMX/releases if you want an earlier release version) so the folder CumulusMX is the same folder as that which has "Cumulus.ini" in it. The unzip ensures all the files that need to be in sub-folders go into correct sub-folders.

Your log files in the data folder and any NOAA reports you may (they are optional) have created in Reports folder are available to MX.

You should read Category:Ini Files page, as you might need to edit some items in the .ini files.

For the .txt files, you need to check that all lines are consistent in using the same character to separate the 3 parts of the date (see , and the same character is used throughout to separate the items in list of fields.

  • Cumulus 1 will accept any character (except space, a digit, or the character used to separate fields in a list) as a separator for the date parts
  • MX will only accept the character defined in your locale (for a Windows PC that is actually set in Control Panel which Windows does not make easy to access preferring you to use its Settings app.
  • There is a Clock and Region section in Control Panel and in the Region window you define the separator MX will use in the Short date item, most easily by clicking additional settings).
  • Now ensure that is same character as used in al lines of your .txt log files.
    • If you have some lines using say "/" and some using "." or "-" as date separator, then there are many editors available that offer a global replace.
      • As an example, Notepad++ has a Replace All in All Opened Documents, so you can open multiple documents and do a global replace of "/" into "-" very easily. Notepad++ saves the file in the same encoding as it was before, but you can also check it is UTF-8 with no Byte Order Mark via the menus.
      • Note that you cannot easily replace "." or "-" globally in dates, because those appear as valid characters in fields. To edit those, you would need to open the files in a spreadsheet editor like Libre Office, you need to ensure that the dates column is treated as text, then select that column and do a replace in just the date column, and then save as a CSV format file changing the extension to .txt. There is more information on this in relevant log file articles.
    • The basic Microsoft Notepad that comes with Windows has a Replace option in its Edit menu, but some versions of this editor (check Save As options) don't allow you to pick "UTF-8" encoding (if that is not already shown) when saving to ensure MX can read the output.
    • Also be aware when using Google editors that they may save the file in the wrong format unless you can choose a UTF-8 no BOM option.


Alternatively, to run Cumulus MX with your existing Cumulus data, first take a back up copy of your existing Cumulus directory.

Next obtain the MX distribution release as a zip as per previous option.

Now unzip Cumulus MX into the original Cumulus folder. The new CumulusMX.exe should end up in same folder as existing Cumulus.ini, there will be other files in this folder, and there will be some new folders you have not seen before like interface and MXDiags, but MX continues to use the existing sub-folders (like data and backup) without any change of name.

This saves you from copying any of your Cumulus 1 files, they just stay where they are and get used by MX.

Where your existing Cumulus.ini_(Cumulus_1) file makes reference to local folders (in say Extra Web Files), those references stay valid. The only edit you will make to configuration that affects Cumulus.ini is dependent on your weather station type, as explained later MX uses a different parameter to refer to the port used by the weather station.

Be aware that MX changes the date formats in some files, so that Cumulus 1 can no longer understand them, so be cautious about copying log files (.ini and .txt) back to your Cumulus 1 back-up should you want to revert to using Cumulus 1.

Some other issues that were described in previous sub-section will apply in this case, because for MX this approach (preserving Cumulus 1 in a new location) is no different to previous.


These notes apply whether you are installing in a new location on your PC or installing MX on a different device.

Obtain the MX download (from Software for latest version or from https://github.com/cumulusmx/CumulusMX/releases if you want an earlier release version).

When you do the unzip as explained below, it ensures all the files that need to be in sub-folders go into correct sub-folders. You then add various folders and files from your Cumulus 1 installation into correct places. As said before, this sub-section gives only a brief mention of possible issues with existing files, later sections will explain those in more detail.

  1. First create a new directory (recommended name CumulusMX) and unzip the contents into it.
    • For a pi, the instruction might be unzip -o CumulusMXDist3nnn.zip where nnn is the last 3 digits of the build number.
  2. Then copy (or file transfer over)
    • your previous data folder contents into the new data folder created by unzipping, as before you might need to edit some log files
    • your previous Reports folder contents (if any) into the new Reports folder created by unzipping
    • your Cumulus.ini_(Cumulus_1) file goes into the top level folder, the one with ExportMySQL.exe, CumulusMX.exe and the .dll files,
      • Check that destination file, it must be "Cumulus.ini" (ensure it starts with capital letter and all other letters are lower case)
      • In the new "Cumulus.ini" edit any lines that made reference to the old windows location. Remember, that only windows uses "\" in paths, and your new device will require reference to new locations. Even if you are still using windows, you may need to make changes to reflect that the files are now in a new location.
      • You can delay changing other settings (like the port used to access your weather station which uses a different parameter in MX) when you have access to the Settings pages in the MX admin interface
    • any other configuration files that you may have created (e.g. strings.ini, twitter.txt etc).

The big advantage of this approach is that anytime you are not running MX you can go back to Cumulus 1 and let it run from where it left off (subject to availability of past data in your weather station, and possibly unplugging weather station from one device and plugging it into PC). Obviously you cannot run Cumulus 1 and MX at the same time accessing the same weather station (even if both are on same device and so no unplugging and plugging in is needed).