Mosquito season in Wallowa County, OR: when it starts and ends
Mosquito months in Wallowa County
In a normal year mosquito season in Wallowa County, OR starts around May 11 and ends around October 4, about 21 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Wallowa County, and when
- Start tipping out standing water weekly by April 27.
- Book any yard treatment for mid May, ahead of the August peak.
- Repellent can go away after October 4.
- No West Nile cases since 2016, so bites in Wallowa County are a nuisance; check window screens.
Wallowa County against the rest of OR
Wallowa County has the 29th longest season of 36 OR counties, at 146 days against 225 in Curry County and 95 in Klamath County. Its mean temperature is 45.1°F.
- Hood River County: May 11 to October 7 (149 days, 0 WNV)
- Harney County: May 7 to October 1 (147 days, 7 WNV)
- Baker County: May 8 to September 27 (142 days, 8 WNV)
- Lake County: May 10 to September 28 (141 days, 0 WNV)
West Nile in Wallowa County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Wallowa County (0 neuroinvasive) across 1 year. The worst was 2007 with 1; the latest was 2007.
More: how the dates are worked out · when mosquitoes go away for the winter.