Mosquito season in Boundary County, ID: when it starts and ends
Mosquito months in Boundary County
In a normal year mosquito season in Boundary County, ID starts around April 30 and ends around October 1, about 22 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Boundary County, and when
- Start tipping out standing water weekly by April 16.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 1.
- No West Nile cases since 2016, so bites in Boundary County are a nuisance; check window screens.
Boundary County against the rest of ID
Boundary County has the 17th longest season of 44 ID counties, at 154 days against 194 in Canyon County and 85 in Fremont County. Its mean temperature is 45.6°F.
- Kootenai County: May 1 to October 8 (160 days, 2 WNV)
- Benewah County: May 3 to October 7 (157 days, 0 WNV)
- Latah County: May 4 to October 5 (154 days, 0 WNV)
- Bannock County: May 4 to October 4 (153 days, 1 WNV)
West Nile in Boundary County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Boundary County (1 neuroinvasive) across 1 year. The worst was 2007 with 1; the latest was 2007.
See how the dates are worked out, and when the season starts across the US.