Mosquito season in Skamania County, WA: when it starts and ends

Mosquito months in Skamania County

In a normal year mosquito season in Skamania County, WA starts around May 3 and ends around October 9, about 23 weeks.

1. Jan
2. Feb
3. Mar
4. Apr
5. May
6. Jun
7. Jul
8. Aug
9. Sep
10. Oct
11. Nov
12. Dec

What to do in Skamania County, and when

• Start tipping out standing water weekly by April 19.
• Book any yard treatment for early May, ahead of the July peak.
• Repellent can go away after October 9.
• No West Nile cases since 2016, so bites in Skamania County are a nuisance; check window screens.

Skamania County against the rest of WA

Skamania County has the 31st longest season of 39 WA counties, at 159 days against 205 in Walla Walla County and 132 in Asotin County. Its mean temperature is 47.5°F.

• Jefferson County: May 1 to October 13 (166 days, 0 WNV)
• Douglas County: April 29 to October 9 (163 days, 0 WNV)
• Klickitat County: May 2 to October 7 (158 days, 0 WNV)
• King County: May 8 to October 10 (155 days, 8 WNV)

West Nile in Skamania County

CDC ArboNET lists no human West Nile cases for Skamania County from 1999 to 2025.

Background: when the season starts across the US; how the dates are worked out.