Mosquito season in Lake County, MN: when it starts and ends
Mosquito months in Lake County
In a normal year mosquito season in Lake County, MN starts around May 16 and ends around September 25, about 19 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Lake County, and when
- Start tipping out standing water weekly by May 2.
- Book any yard treatment for mid May, ahead of the July peak.
- Repellent can go away after September 25.
- 1 West Nile case since 2016 (last 2024): you should use repellent at dusk July, more so if over 60.
Lake County against the rest of MN
Lake County has the 86th longest season of 87 MN counties, at 132 days against 176 in Winona County and 118 in Cook County. Its mean temperature is 37.8°F.
- Koochiching County: May 12 to September 25 (137 days, 1 WNV)
- St. Louis County: May 13 to September 26 (136 days, 7 WNV)
- Cook County: June 2 to September 28 (118 days, 0 WNV)
West Nile in Lake County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Lake County (1 neuroinvasive) across 1 year. The worst was 2024 with 1; the latest was 2024.
Background: when mosquitoes go away for the winter; how the dates are worked out.