Mosquito season in Barron County, WI: when it starts and ends
Mosquito months in Barron County
In a normal year mosquito season in Barron County, WI starts around May 2 and ends around October 6, about 22 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Barron County, and when
- Start tipping out standing water weekly by April 18.
- 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 2025): you should use repellent at dusk July, more so if over 60.
Barron County against the rest of WI
Barron County has the 46th longest season of 72 WI counties, at 157 days against 180 in La Crosse County and 139 in Rusk County. Its mean temperature is 42.7°F.
- Burnett County: May 1 to October 6 (158 days, 0 WNV)
- St. Croix County: May 2 to October 7 (158 days, 4 WNV)
- Marathon County: May 2 to October 6 (157 days, 3 WNV)
- Shawano County: May 2 to October 7 (157 days, 4 WNV)
West Nile in Barron County
From 1999 to 2025, CDC ArboNET counted 11 human West Nile cases in Barron County (3 neuroinvasive) across 4 years. The worst was 2002 with 8; the latest was 2025.
See how the dates are worked out, and when mosquitoes go away for the winter.