Mosquito season in Osceola County, MI: when it starts and ends
Mosquito months in Osceola County
In a normal year mosquito season in Osceola County, MI starts around May 5 and ends around October 7, about 22 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Osceola County, and when
- Start tipping out standing water weekly by April 21.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 7.
- No West Nile cases since 2016, so bites in Osceola County are a nuisance; check window screens.
Osceola County against the rest of MI
Osceola County has the 51st longest season of 83 MI counties, at 156 days against 189 in Allegan County and 124 in Iron County. Its mean temperature is 44.3°F.
- Iosco County: May 6 to October 10 (157 days, 0 WNV)
- Montcalm County: May 4 to October 7 (156 days, 3 WNV)
- Antrim County: May 8 to October 11 (156 days, 0 WNV)
- Ogemaw County: May 5 to October 7 (155 days, 0 WNV)
West Nile in Osceola County
CDC ArboNET lists no human West Nile cases for Osceola County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 3 of those years.
More: how the dates are worked out · when mosquitoes go away for the winter.