Mosquito season in Dearborn County, IN: when it starts and ends
Mosquito months in Dearborn County
In a normal year mosquito season in Dearborn County, IN starts around April 17 and ends around October 25, about 27 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Dearborn County, and when
- Start tipping out standing water weekly by April 3.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 25.
- No West Nile cases since 2016, so bites in Dearborn County are a nuisance; check window screens.
Dearborn County against the rest of IN
Dearborn County has the 67th longest season of 92 IN counties, at 191 days against 231 in Floyd County and 177 in Steuben County. Its mean temperature is 51.9°F.
- Newton County: April 15 to October 22 (191 days, 0 WNV)
- White County: April 15 to October 23 (191 days, 1 WNV)
- Benton County: April 15 to October 22 (190 days, 0 WNV)
- Putnam County: April 15 to October 22 (190 days, 0 WNV)
West Nile in Dearborn County
From 1999 to 2025, CDC ArboNET counted 5 human West Nile cases in Dearborn County (4 neuroinvasive) across 3 years. The worst was 2002 with 3; the latest was 2012.
More: how the dates are worked out · when mosquitoes go away for the winter.