Mosquito season in Owyhee County, ID: when it starts and ends
Mosquito months in Owyhee County
In a normal year mosquito season in Owyhee County, ID starts around May 9 and ends around October 9, about 22 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Owyhee County, and when
- Start tipping out standing water weekly by April 25.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 9.
- 11 West Nile cases since 2016: you should wear EPA-registered repellent at dusk July to July, and check ID spray notices.
Owyhee County against the rest of ID
Owyhee County has the 20th longest season of 44 ID counties, at 153 days against 194 in Canyon County and 85 in Fremont County. Its mean temperature is 47°F.
- Latah County: May 4 to October 5 (154 days, 0 WNV)
- Bannock County: May 4 to October 4 (153 days, 1 WNV)
- Lincoln County: May 8 to October 7 (152 days, 2 WNV)
- Bonner County: May 3 to October 1 (151 days, 0 WNV)
West Nile in Owyhee County
From 1999 to 2025, CDC ArboNET counted 55 human West Nile cases in Owyhee County (15 neuroinvasive) across 14 years. The worst was 2006 with 32; the latest was 2023.
See how the dates are worked out, and reading the West Nile counts.