Mosquito season in Winona County, MN: when it starts and ends
Mosquito months in Winona County
In a normal year mosquito season in Winona County, MN starts around April 23 and ends around October 15, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Winona County, and when
- Start tipping out standing water weekly by April 9.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 15.
- 1 West Nile case since 2016 (last 2025): you should use repellent at dusk July to August, more so if over 60.
Winona County against the rest of MN
Winona County has the 1st longest season of 87 MN counties, at 176 days against 176 in Winona County and 118 in Cook County. Its mean temperature is 46.9°F.
- Blue Earth County: April 23 to October 14 (173 days, 9 WNV)
- Faribault County: April 24 to October 13 (172 days, 0 WNV)
West Nile in Winona County
From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Winona County (2 neuroinvasive) across 2 years. The worst was 2025 with 1; the latest was 2025.
More: how the dates are worked out · when the season starts across the US.