Mosquito season in Canyon County, ID: when it starts and ends
Mosquito months in Canyon County
In a normal year mosquito season in Canyon County, ID starts around April 9 and ends around October 21, about 28 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Canyon County, and when
- Start tipping out standing water weekly by March 26.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 21.
- 20 West Nile cases since 2016: you should wear EPA-registered repellent at dusk July to August, and check ID spray notices.
Canyon County against the rest of ID
Canyon County has the 1st longest season of 44 ID counties, at 194 days against 194 in Canyon County and 85 in Fremont County. Its mean temperature is 52.3°F.
- Payette County: April 9 to October 19 (194 days, 6 WNV)
- Ada County: April 12 to October 23 (193 days, 36 WNV)
West Nile in Canyon County
From 1999 to 2025, CDC ArboNET counted 259 human West Nile cases in Canyon County (56 neuroinvasive) across 17 years. The worst was 2006 with 180; the latest was 2024.
More: how the dates are worked out · reading the West Nile counts.