Mosquito season in Blue Earth County, MN: when it starts and ends
Mosquito months in Blue Earth County
In a normal year mosquito season in Blue Earth County, MN starts around April 23 and ends around October 14, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Blue Earth 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 14.
- 9 West Nile cases since 2016 (last 2025): you should use repellent at dusk July to August, more so if over 60.
Blue Earth County against the rest of MN
Blue Earth County has the 2nd longest season of 87 MN counties, at 173 days against 176 in Winona County and 118 in Cook County. Its mean temperature is 46.1°F.
- Winona County: April 23 to October 15 (176 days, 1 WNV)
- Faribault County: April 24 to October 13 (172 days, 0 WNV)
- Ramsey County: April 24 to October 13 (172 days, 20 WNV)
West Nile in Blue Earth County
From 1999 to 2025, CDC ArboNET counted 20 human West Nile cases in Blue Earth County (9 neuroinvasive) across 11 years. The worst was 2003 with 5; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.