Mosquito season in Keweenaw County, MI: when it starts and ends
Mosquito months in Keweenaw County
In a normal year mosquito season in Keweenaw County, MI starts around May 16 and ends around October 2, about 20 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Keweenaw 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 October 2.
- 1 West Nile case since 2016 (last 2021): you should use repellent at dusk July, more so if over 60.
Keweenaw County against the rest of MI
Keweenaw County has the 79th longest season of 83 MI counties, at 139 days against 189 in Allegan County and 124 in Iron County. Its mean temperature is 41°F.
- Luce County: May 14 to October 2 (141 days, 0 WNV)
- Schoolcraft County: May 17 to October 4 (140 days, 0 WNV)
- Alger County: May 18 to October 4 (139 days, 0 WNV)
- Baraga County: May 14 to September 29 (138 days, 0 WNV)
West Nile in Keweenaw County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Keweenaw County (1 neuroinvasive) across 1 year. The worst was 2021 with 1; the latest was 2021.
More: how the dates are worked out · when the season starts across the US.