Mosquito season in Clallam County, WA: when it starts and ends
Mosquito months in Clallam County
In a normal year mosquito season in Clallam County, WA starts around April 30 and ends around October 13, about 24 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Clallam County, and when
- Start tipping out standing water weekly by April 16.
- Book any yard treatment for late April, ahead of the August peak.
- Repellent can go away after October 13.
- 1 West Nile case since 2016 (last 2022): you should use repellent at dusk August, more so if over 60.
Clallam County against the rest of WA
Clallam County has the 28th longest season of 39 WA counties, at 166 days against 205 in Walla Walla County and 132 in Asotin County. Its mean temperature is 49.1°F.
- Spokane County: April 26 to October 10 (167 days, 12 WNV)
- Snohomish County: April 29 to October 12 (166 days, 0 WNV)
- Jefferson County: May 1 to October 13 (166 days, 0 WNV)
- Douglas County: April 29 to October 9 (163 days, 0 WNV)
West Nile in Clallam County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Clallam County (1 neuroinvasive) across 1 year. The worst was 2022 with 1; the latest was 2022.
See how the dates are worked out, and when mosquitoes go away for the winter.