Mosquito season in Macomb County, MI: when it starts and ends
Mosquito months in Macomb County
In a normal year mosquito season in Macomb County, MI starts around April 26 and ends around October 19, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Macomb County, and when
- Start tipping out standing water weekly by April 12.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 19.
- 50 West Nile cases since 2016: you should wear EPA-registered repellent at dusk July to August, and check MI spray notices.
Macomb County against the rest of MI
Macomb County has the 16th longest season of 83 MI counties, at 176 days against 189 in Allegan County and 124 in Iron County. Its mean temperature is 48.6°F.
- Branch County: April 23 to October 16 (176 days, 0 WNV)
- Oakland County: April 24 to October 17 (176 days, 62 WNV)
- Hillsdale County: April 24 to October 16 (175 days, 2 WNV)
- Barry County: April 25 to October 16 (174 days, 2 WNV)
West Nile in Macomb County
From 1999 to 2025, CDC ArboNET counted 228 human West Nile cases in Macomb County (189 neuroinvasive) across 21 years. The worst was 2002 with 109; the latest was 2025.
Background: reading the West Nile counts; how the dates are worked out.