Mosquito season in Wayne County, MI: when it starts and ends
Mosquito months in Wayne County
In a normal year mosquito season in Wayne County, MI starts around April 21 and ends around October 21, about 26 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Wayne County, and when
- Start tipping out standing water weekly by April 7.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 21.
- 110 West Nile cases since 2016: you should wear EPA-registered repellent at dusk July to August, and check MI spray notices.
Wayne County against the rest of MI
Wayne County has the 6th longest season of 83 MI counties, at 183 days against 189 in Allegan County and 124 in Iron County. Its mean temperature is 49.8°F.
- Monroe County: April 21 to October 22 (184 days, 7 WNV)
- Kalamazoo County: April 19 to October 19 (183 days, 6 WNV)
- Lenawee County: April 20 to October 19 (182 days, 3 WNV)
- Calhoun County: April 21 to October 19 (181 days, 3 WNV)
West Nile in Wayne County
From 1999 to 2025, CDC ArboNET counted 501 human West Nile cases in Wayne County (449 neuroinvasive) across 23 years. The worst was 2002 with 186; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.