Mosquito season in Teton County, WY: when it starts and ends
Mosquito months in Teton County
In a normal year mosquito season in Teton County, WY starts around June 20 and ends around September 3, about 11 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Teton County, and when
- Start tipping out standing water weekly by June 6.
- Book any yard treatment for mid June, ahead of the July peak.
- Repellent can go away after September 3.
- No West Nile cases since 2016, so bites in Teton County are a nuisance; check window screens.
Teton County against the rest of WY
Teton County has the 23rd longest season of 23 WY counties, at 75 days against 163 in Big Horn County and 75 in Teton County. Its mean temperature is 33.4°F.
- Lincoln County: June 8 to September 11 (95 days, 0 WNV)
- Sublette County: June 6 to September 4 (90 days, 0 WNV)
West Nile in Teton County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Teton County (1 neuroinvasive) across 1 year. The worst was 2012 with 1; the latest was 2012.
More: how the dates are worked out · when mosquitoes go away for the winter.