Mosquito season in Wibaux County, MT: when it starts and ends
Mosquito months in Wibaux County
In a normal year mosquito season in Wibaux County, MT starts around May 17 and ends around September 26, about 19 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Wibaux County, and when
- Start tipping out standing water weekly by May 3.
- Book any yard treatment for mid May, ahead of the July peak.
- Repellent can go away after September 26.
- No West Nile cases since 2016, so bites in Wibaux County are a nuisance; check window screens.
Wibaux County against the rest of MT
Wibaux County has the 36th longest season of 56 MT counties, at 132 days against 163 in Dawson County and 89 in Gallatin County. Its mean temperature is 42.7°F.
- Stillwater County: May 13 to September 26 (136 days, 1 WNV)
- Wheatland County: May 16 to September 27 (134 days, 0 WNV)
- Fergus County: May 20 to September 28 (132 days, 0 WNV)
- Roosevelt County: May 14 to September 22 (131 days, 1 WNV)
West Nile in Wibaux County
From 1999 to 2025, CDC ArboNET counted 7 human West Nile cases in Wibaux County (1 neuroinvasive) across 4 years. The worst was 2003 with 3; the latest was 2015.
More: how the dates are worked out · when the season starts across the US.