Mosquito season in Oconto County, WI: when it starts and ends
Mosquito months in Oconto County
In a normal year mosquito season in Oconto County, WI starts around May 4 and ends around October 6, about 22 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Oconto County, and when
- Start tipping out standing water weekly by April 20.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 6.
- 2 West Nile cases since 2016 (last 2017): you should use repellent at dusk July, more so if over 60.
Oconto County against the rest of WI
Oconto County has the 52nd longest season of 72 WI counties, at 155 days against 180 in La Crosse County and 139 in Rusk County. Its mean temperature is 43.1°F.
- Washburn County: May 2 to October 6 (156 days, 0 WNV)
- Pierce County: May 3 to October 5 (155 days, 1 WNV)
- Door County: May 9 to October 11 (155 days, 0 WNV)
- Menominee County: May 4 to October 5 (154 days, 0 WNV)
West Nile in Oconto County
From 1999 to 2025, CDC ArboNET counted 3 human West Nile cases in Oconto County (3 neuroinvasive) across 2 years. The worst was 2017 with 2; the latest was 2017.
Background: when mosquitoes go away for the winter; how the dates are worked out.