Mosquito season in Jackson County, WI: when it starts and ends
Mosquito months in Jackson County
In a normal year mosquito season in Jackson County, WI starts around April 30 and ends around October 7, about 23 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Jackson County, and when
- Start tipping out standing water weekly by April 16.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 7.
- No West Nile cases since 2016, so bites in Jackson County are a nuisance; check window screens.
Jackson County against the rest of WI
Jackson County has the 40th longest season of 72 WI counties, at 160 days against 180 in La Crosse County and 139 in Rusk County. Its mean temperature is 43.8°F.
- Trempealeau County: April 30 to October 8 (161 days, 7 WNV)
- Wood County: April 30 to October 8 (161 days, 5 WNV)
- Vernon County: April 30 to October 8 (160 days, 0 WNV)
- Portage County: May 1 to October 8 (160 days, 1 WNV)
West Nile in Jackson County
CDC ArboNET lists no human West Nile cases for Jackson County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 7 of those years.
See how the dates are worked out, and when the season starts across the US.