Mosquito season in Harney County, OR: when it starts and ends
Mosquito months in Harney County
In a normal year mosquito season in Harney County, OR starts around May 7 and ends around October 1, about 21 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Harney County, and when
- Start tipping out standing water weekly by April 23.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 1.
- 7 West Nile cases since 2016 (last 2023): you should use repellent at dusk July, more so if over 60.
Harney County against the rest of OR
Harney County has the 28th longest season of 36 OR counties, at 147 days against 225 in Curry County and 95 in Klamath County. Its mean temperature is 46.1°F.
- Marion County: May 10 to October 12 (155 days, 0 WNV)
- Hood River County: May 11 to October 7 (149 days, 0 WNV)
- Wallowa County: May 11 to October 4 (146 days, 0 WNV)
- Baker County: May 8 to September 27 (142 days, 8 WNV)
West Nile in Harney County
From 1999 to 2025, CDC ArboNET counted 15 human West Nile cases in Harney County (7 neuroinvasive) across 5 years. The worst was 2006 with 6; the latest was 2023.
More: how the dates are worked out · reading the West Nile counts.