Mosquito season in Davis County, UT: when it starts and ends
Mosquito months in Davis County
In a normal year mosquito season in Davis County, UT starts around April 16 and ends around October 20, about 27 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Davis County, and when
- Start tipping out standing water weekly by April 2.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 20.
- 36 West Nile cases since 2016: you should wear EPA-registered repellent at dusk July to August, and check UT spray notices.
Davis County against the rest of UT
Davis County has the 5th longest season of 29 UT counties, at 188 days against 210 in Salt Lake County and 82 in Summit County. Its mean temperature is 52.2°F.
- Grand County: April 8 to October 26 (201 days, 4 WNV)
- Utah County: April 9 to October 25 (199 days, 28 WNV)
- Garfield County: April 22 to October 20 (181 days, 0 WNV)
- Washington County: April 24 to October 22 (181 days, 9 WNV)
West Nile in Davis County
From 1999 to 2025, CDC ArboNET counted 57 human West Nile cases in Davis County (33 neuroinvasive) across 12 years. The worst was 2006 with 11; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.