Mosquito season in Deer Lodge County, MT: when it starts and ends
Mosquito months in Deer Lodge County
In a normal year mosquito season in Deer Lodge County, MT starts around May 25 and ends around September 23, about 17 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Deer Lodge County, and when
- Start tipping out standing water weekly by May 11.
- Book any yard treatment for late May, ahead of the July peak.
- Repellent can go away after September 23.
- No West Nile cases since 2016, so bites in Deer Lodge County are a nuisance; check window screens.
Deer Lodge County against the rest of MT
Deer Lodge County has the 47th longest season of 56 MT counties, at 121 days against 163 in Dawson County and 89 in Gallatin County. Its mean temperature is 41.2°F.
- Jefferson County: May 22 to September 21 (122 days, 1 WNV)
- Missoula County: May 23 to September 22 (122 days, 0 WNV)
- Daniels County: May 19 to September 16 (120 days, 0 WNV)
- Judith Basin County: May 25 to September 18 (116 days, 0 WNV)
West Nile in Deer Lodge County
CDC ArboNET lists no human West Nile cases for Deer Lodge County from 1999 to 2025.
Background: when the season starts across the US; how the dates are worked out.