Gale Days
Shown in View menu displays for This month, This period, and This year. Cumulus uses the definition of a gale as used by the UK Met Office and the US NWS (and also, Steve Loft suspects, by the Australian BOM); that is, sustained wind speeds of 39 mph (62 km/h, 34 kts) or more, equivalent to Beaufort F8 or above. Gale days is thus the count of days in selected period where the highest average wind speed meets or exceeds this threshold.