Mosquito season in Ohio County, IN: when it starts and ends
Mosquito months in Ohio County
In a normal year mosquito season in Ohio County, IN starts around April 11 and ends around October 31, about 29 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Ohio County, and when
- Start tipping out standing water weekly by March 28.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 31.
- 1 West Nile case since 2016 (last 2025): you should use repellent at dusk June to August, more so if over 60.
Ohio County against the rest of IN
Ohio County has the 36th longest season of 92 IN counties, at 203 days against 231 in Floyd County and 177 in Steuben County. Its mean temperature is 54.2°F.
- Owen County: April 7 to October 27 (203 days, 0 WNV)
- Shelby County: April 8 to October 28 (203 days, 1 WNV)
- Marion County: April 8 to October 27 (202 days, 18 WNV)
- Hendricks County: April 9 to October 27 (201 days, 1 WNV)
West Nile in Ohio County
From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Ohio County (2 neuroinvasive) across 2 years. The worst was 2025 with 1; the latest was 2025.
Background: when mosquitoes go away for the winter; how the dates are worked out.