Mosquito season in Yamhill County, OR: when it starts and ends
Mosquito months in Yamhill County
In a normal year mosquito season in Yamhill County, OR starts around April 10 and ends around October 29, about 29 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Yamhill County, and when
- Start tipping out standing water weekly by March 27.
- Book any yard treatment for early April, ahead of the August peak.
- Repellent can go away after October 29.
- No West Nile cases since 2016, so bites in Yamhill County are a nuisance; check window screens.
Yamhill County against the rest of OR
Yamhill County has the 6th longest season of 36 OR counties, at 202 days against 225 in Curry County and 95 in Klamath County. Its mean temperature is 53.2°F.
- Josephine County: April 4 to November 1 (211 days, 0 WNV)
- Douglas County: April 7 to October 29 (204 days, 0 WNV)
- Lane County: April 16 to October 29 (197 days, 1 WNV)
- Lincoln County: April 27 to November 8 (195 days, 0 WNV)
West Nile in Yamhill County
CDC ArboNET lists no human West Nile cases for Yamhill County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 1 of those years.
More: how the dates are worked out · when the season starts across the US.