Mosquito season in Lake County, OR: when it starts and ends

Mosquito months in Lake County

In a normal year mosquito season in Lake County, OR starts around May 10 and ends around September 28, about 20 weeks.

What to do in Lake County, and when

Start tipping out standing water weekly by April 26.
Book any yard treatment for early May, ahead of the July peak.
Repellent can go away after September 28.
No West Nile cases since 2016, so bites in Lake County are a nuisance; check window screens.

Lake County against the rest of OR

Lake County has the 31st longest season of 36 OR counties, at 141 days against 225 in Curry County and 95 in Klamath County. Its mean temperature is 47.8°F.

Wallowa County: May 11 to October 4 (146 days, 0 WNV)
Baker County: May 8 to September 27 (142 days, 8 WNV)
Crook County: May 12 to September 30 (141 days, 0 WNV)
Grant County: May 13 to October 1 (141 days, 1 WNV)

West Nile in Lake County

CDC ArboNET lists no human West Nile cases for Lake County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 5 of those years.

Background: when mosquitoes go away for the winter; how the dates are worked out.