Mosquito season in Alger County, MI: when it starts and ends
Mosquito months in Alger County
In a normal year mosquito season in Alger County, MI starts around May 18 and ends around October 4, about 20 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Alger County, and when
- Start tipping out standing water weekly by May 4.
- Book any yard treatment for mid May, ahead of the July peak.
- Repellent can go away after October 4.
- No West Nile cases since 2016, so bites in Alger County are a nuisance; check window screens.
Alger County against the rest of MI
Alger County has the 80th longest season of 83 MI counties, at 139 days against 189 in Allegan County and 124 in Iron County. Its mean temperature is 41.5°F.
- Schoolcraft County: May 17 to October 4 (140 days, 0 WNV)
- Keweenaw County: May 16 to October 2 (139 days, 1 WNV)
- Baraga County: May 14 to September 29 (138 days, 0 WNV)
- Houghton County: May 17 to September 30 (137 days, 0 WNV)
West Nile in Alger County
CDC ArboNET lists no human West Nile cases for Alger County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 8 of those years.
See how the dates are worked out, and when the season starts across the US.