Mosquito season in Wasatch County, UT: when it starts and ends
Mosquito months in Wasatch County
In a normal year mosquito season in Wasatch County, UT starts around June 8 and ends around September 20, about 15 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Wasatch County, and when
- Start tipping out standing water weekly by May 25.
- Book any yard treatment for early June, ahead of the July peak.
- Repellent can go away after September 20.
- No West Nile cases since 2016, so bites in Wasatch County are a nuisance; check window screens.
Wasatch County against the rest of UT
Wasatch County has the 28th longest season of 29 UT counties, at 104 days against 210 in Salt Lake County and 82 in Summit County. Its mean temperature is 39.6°F.
- Piute County: May 31 to September 23 (115 days, 0 WNV)
- Rich County: May 30 to September 11 (104 days, 0 WNV)
- Summit County: June 19 to September 9 (82 days, 0 WNV)
West Nile in Wasatch County
CDC ArboNET lists no human West Nile cases for Wasatch County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 2 of those years.
See how the dates are worked out, and when mosquitoes go away for the winter.