Mosquito season in Branch County, MI: when it starts and ends
Mosquito months in Branch County
In a normal year mosquito season in Branch County, MI starts around April 23 and ends around October 16, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Branch County, and when
- Start tipping out standing water weekly by April 9.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 16.
- No West Nile cases since 2016, so bites in Branch County are a nuisance; check window screens.
Branch County against the rest of MI
Branch County has the 14th longest season of 83 MI counties, at 176 days against 189 in Allegan County and 124 in Iron County. Its mean temperature is 48.1°F.
- St. Joseph County: April 22 to October 18 (179 days, 3 WNV)
- Cass County: April 24 to October 20 (179 days, 2 WNV)
- Oakland County: April 24 to October 17 (176 days, 62 WNV)
- Macomb County: April 26 to October 19 (176 days, 50 WNV)
West Nile in Branch County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Branch County (1 neuroinvasive) across 1 year. The worst was 2004 with 1; the latest was 2004.
See how the dates are worked out, and when mosquitoes go away for the winter.