Mosquito season in Douglas County, WI: when it starts and ends
Mosquito months in Douglas County
In a normal year mosquito season in Douglas County, WI starts around May 7 and ends around October 4, about 22 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Douglas 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 4.
- 3 West Nile cases since 2016 (last 2024): you should use repellent at dusk July, more so if over 60.
Douglas County against the rest of WI
Douglas County has the 59th longest season of 72 WI counties, at 151 days against 180 in La Crosse County and 139 in Rusk County. Its mean temperature is 41.8°F.
- Taylor County: May 4 to October 3 (152 days, 0 WNV)
- Juneau County: May 5 to October 3 (151 days, 3 WNV)
- Lincoln County: May 7 to October 2 (148 days, 1 WNV)
- Sawyer County: May 7 to October 2 (148 days, 2 WNV)
West Nile in Douglas County
From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Douglas County (3 neuroinvasive) across 4 years. The worst was 2024 with 1; the latest was 2024.
See how the dates are worked out, and when the season starts across the US.