Mosquito season in Douglas County, MN: when it starts and ends
Mosquito months in Douglas County
In a normal year mosquito season in Douglas County, MN starts around May 2 and ends around October 6, 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 18.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 6.
- 6 West Nile cases since 2016 (last 2025): you should use repellent at dusk July to July, more so if over 60.
Douglas County against the rest of MN
Douglas County has the 54th longest season of 87 MN counties, at 157 days against 176 in Winona County and 118 in Cook County. Its mean temperature is 42.5°F.
- Lincoln County: May 2 to October 7 (158 days, 2 WNV)
- Clay County: May 1 to October 5 (157 days, 30 WNV)
- Dodge County: May 2 to October 5 (156 days, 1 WNV)
- Meeker County: May 2 to October 5 (156 days, 2 WNV)
West Nile in Douglas County
From 1999 to 2025, CDC ArboNET counted 14 human West Nile cases in Douglas County (6 neuroinvasive) across 11 years. The worst was 2025 with 3; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.