Mosquito season in Mason County, MI: when it starts and ends
Mosquito months in Mason County
In a normal year mosquito season in Mason County, MI starts around May 2 and ends around October 11, about 23 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Mason County, and when
- Start tipping out standing water weekly by April 18.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 11.
- No West Nile cases since 2016, so bites in Mason County are a nuisance; check window screens.
Mason County against the rest of MI
Mason County has the 40th longest season of 83 MI counties, at 163 days against 189 in Allegan County and 124 in Iron County. Its mean temperature is 46.1°F.
- Benzie County: May 3 to October 14 (164 days, 0 WNV)
- Grand Traverse County: May 3 to October 14 (164 days, 1 WNV)
- Muskegon County: May 5 to October 15 (163 days, 2 WNV)
- Huron County: May 6 to October 16 (163 days, 0 WNV)
West Nile in Mason County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Mason County (0 neuroinvasive) across 1 year. The worst was 2006 with 1; the latest was 2006.
More: how the dates are worked out · when mosquitoes go away for the winter.