Mosquito season in Alpena County, MI: when it starts and ends
Mosquito months in Alpena County
In a normal year mosquito season in Alpena County, MI starts around May 10 and ends around October 8, about 22 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Alpena County, and when
- Start tipping out standing water weekly by April 26.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 8.
- No West Nile cases since 2016, so bites in Alpena County are a nuisance; check window screens.
Alpena County against the rest of MI
Alpena County has the 60th longest season of 83 MI counties, at 151 days against 189 in Allegan County and 124 in Iron County. Its mean temperature is 43.9°F.
- Presque Isle County: May 8 to October 8 (153 days, 1 WNV)
- Cheboygan County: May 9 to October 8 (152 days, 0 WNV)
- Montmorency County: May 8 to October 5 (150 days, 0 WNV)
- Ontonagon County: May 10 to October 7 (150 days, 1 WNV)
West Nile in Alpena County
CDC ArboNET lists no human West Nile cases for Alpena County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 5 of those years.
See how the dates are worked out, and when the season starts across the US.