Mosquito season in Sheboygan County, WI: when it starts and ends
Mosquito months in Sheboygan County
In a normal year mosquito season in Sheboygan County, WI starts around May 3 and ends around October 17, about 24 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Sheboygan County, and when
- Start tipping out standing water weekly by April 19.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 17.
- 3 West Nile cases since 2016 (last 2024): you should use repellent at dusk July to August, more so if over 60.
Sheboygan County against the rest of WI
Sheboygan County has the 22nd longest season of 72 WI counties, at 166 days against 180 in La Crosse County and 139 in Rusk County. Its mean temperature is 47.1°F.
- Richland County: April 27 to October 12 (168 days, 0 WNV)
- Iowa County: April 27 to October 11 (167 days, 1 WNV)
- Dodge County: April 29 to October 11 (165 days, 1 WNV)
- Green Lake County: April 29 to October 11 (165 days, 0 WNV)
West Nile in Sheboygan County
From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Sheboygan County (3 neuroinvasive) across 4 years. The worst was 2024 with 1; the latest was 2024.
Background: when mosquitoes go away for the winter; how the dates are worked out.