Mosquito season in Union County, IN: when it starts and ends
Mosquito months in Union County
In a normal year mosquito season in Union County, IN starts around April 10 and ends around October 26, about 28 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Union County, and when
- Start tipping out standing water weekly by March 27.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 26.
- No West Nile cases since 2016, so bites in Union County are a nuisance; check window screens.
Union County against the rest of IN
Union County has the 41st longest season of 92 IN counties, at 199 days against 231 in Floyd County and 177 in Steuben County. Its mean temperature is 52.2°F.
- Madison County: April 9 to October 27 (201 days, 2 WNV)
- Boone County: April 10 to October 26 (199 days, 1 WNV)
- Carroll County: April 11 to October 26 (198 days, 0 WNV)
- Clinton County: April 11 to October 26 (198 days, 1 WNV)
West Nile in Union County
CDC ArboNET lists no human West Nile cases for Union County from 1999 to 2025, though virus turned up in birds, mosquitoes or horses in 13 of those years.
More: how the dates are worked out · when mosquitoes go away for the winter.