Mosquito season in Valley County, ID: when it starts and ends
Mosquito months in Valley County
In a normal year mosquito season in Valley County, ID starts around May 30 and ends around September 23, about 17 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Valley County, and when
- Start tipping out standing water weekly by May 16.
- Book any yard treatment for late May, ahead of the July peak.
- Repellent can go away after September 23.
- 1 West Nile case since 2016 (last 2023): you should use repellent at dusk July, more so if over 60.
Valley County against the rest of ID
Valley County has the 34th longest season of 44 ID counties, at 116 days against 194 in Canyon County and 85 in Fremont County. Its mean temperature is 40.6°F.
- Clearwater County: May 18 to September 20 (125 days, 0 WNV)
- Teton County: May 22 to September 20 (121 days, 1 WNV)
- Bear Lake County: May 25 to September 16 (114 days, 0 WNV)
- Camas County: May 28 to September 19 (114 days, 0 WNV)
West Nile in Valley County
From 1999 to 2025, CDC ArboNET counted 3 human West Nile cases in Valley County (2 neuroinvasive) across 2 years. The worst was 2006 with 2; the latest was 2023.
See how the dates are worked out, and when mosquitoes go away for the winter.