Mosquito season in Leelanau County, MI: when it starts and ends
Mosquito months in Leelanau County
In a normal year mosquito season in Leelanau County, MI starts around May 6 and ends around October 13, about 23 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Leelanau County, and when
- Start tipping out standing water weekly by April 22.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 13.
- 1 West Nile case since 2016 (last 2023): you should use repellent at dusk July, more so if over 60.
Leelanau County against the rest of MI
Leelanau County has the 47th longest season of 83 MI counties, at 161 days against 189 in Allegan County and 124 in Iron County. Its mean temperature is 45.8°F.
- Mecosta County: May 1 to October 9 (161 days, 0 WNV)
- Arenac County: May 3 to October 11 (161 days, 0 WNV)
- Oscoda County: May 5 to October 9 (157 days, 1 WNV)
- Iosco County: May 6 to October 10 (157 days, 0 WNV)
West Nile in Leelanau County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Leelanau County (1 neuroinvasive) across 1 year. The worst was 2023 with 1; the latest was 2023.
Background: when the season starts across the US; how the dates are worked out.