Wind chill

Wind chill is the apparent temperature felt on exposed skin due to wind. The degree of this phenomenon depends on both air temperature and wind speed. The wind chill temperature (often popularly called the wind chill factor) is always lower than the air temperature. In cases where the apparent temperature is higher than the air temperature, the heat index is used instead.

Wind chill Temperature is only defined for temperatures at or below 10 °C (50 °F) and wind speeds above 4.8 kilometres per hour (3.0 mph).

Some weather stations provide a Wind Chill reading and this will be used by Cumulus, however if one is not provided Cumulus can calculate the Wind Chill. Click Configuration, Station and tick the option to Calculate Wind Chill.

By default Cumulus will provide a Windchill reading for temperatures above 10°C, however if you wish wish to comply with the ten degree limit, edit your cumulus.ini and add the line

UseWindChillCutoff=1

More information on Wind Chill here. Cumulus uses the 'new North American' formula, as described on that page.