Mosquito season in Nicollet County, MN: when it starts and ends
Mosquito months in Nicollet County
In a normal year mosquito season in Nicollet County, MN starts around April 26 and ends around October 11, about 24 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Nicollet County, and when
- Start tipping out standing water weekly by April 12.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 11.
- 2 West Nile cases since 2016 (last 2024): you should use repellent at dusk July to July, more so if over 60.
Nicollet County against the rest of MN
Nicollet County has the 14th longest season of 87 MN counties, at 167 days against 176 in Winona County and 118 in Cook County. Its mean temperature is 44.8°F.
- Dakota County: April 26 to October 11 (167 days, 26 WNV)
- Freeborn County: April 26 to October 11 (167 days, 1 WNV)
- Sibley County: April 26 to October 11 (167 days, 6 WNV)
- Waseca County: April 26 to October 10 (167 days, 2 WNV)
West Nile in Nicollet County
From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Nicollet County (1 neuroinvasive) across 4 years. The worst was 2024 with 1; the latest was 2024.
More: how the dates are worked out · when the season starts across the US.