Mosquito season in Wheatland County, MT: when it starts and ends
Mosquito months in Wheatland County
In a normal year mosquito season in Wheatland County, MT starts around May 16 and ends around September 27, about 19 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Wheatland County, and when
- Start tipping out standing water weekly by May 2.
- Book any yard treatment for mid May, ahead of the July peak.
- Repellent can go away after September 27.
- No West Nile cases since 2016, so bites in Wheatland County are a nuisance; check window screens.
Wheatland County against the rest of MT
Wheatland County has the 35th longest season of 56 MT counties, at 134 days against 163 in Dawson County and 89 in Gallatin County. Its mean temperature is 43.2°F.
- Hill County: May 12 to September 26 (137 days, 2 WNV)
- Stillwater County: May 13 to September 26 (136 days, 1 WNV)
- Wibaux County: May 17 to September 26 (132 days, 0 WNV)
- Fergus County: May 20 to September 28 (132 days, 0 WNV)
West Nile in Wheatland County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Wheatland County (0 neuroinvasive) across 1 year. The worst was 2007 with 1; the latest was 2007.
More: how the dates are worked out · when the season starts across the US.