Mosquito season in Clinton County, IN: when it starts and ends

Mosquito months in Clinton County

In a normal year mosquito season in Clinton County, IN starts around April 11 and ends around October 26, about 28 weeks.

1. Jan
2. Feb
3. Mar
4. Apr
5. May
6. Jun
7. Jul
8. Aug
9. Sep
10. Oct
11. Nov
12. Dec

What to do in Clinton 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 26.
• 1 West Nile case since 2016 (last 2022): you should use repellent at dusk June to August, more so if over 60.

Clinton County against the rest of IN

Clinton County has the 43rd longest season of 92 IN counties, at 198 days against 231 in Floyd County and 177 in Steuben County. Its mean temperature is 51.7°F.

• Union County: April 10 to October 26 (199 days, 0 WNV)
• Carroll County: April 11 to October 26 (198 days, 0 WNV)
• Hancock County: April 11 to October 25 (198 days, 2 WNV)
• Hamilton County: April 11 to October 25 (197 days, 10 WNV)

West Nile in Clinton County

From 1999 to 2025, CDC ArboNET counted 4 human West Nile cases in Clinton County (2 neuroinvasive) across 4 years. The worst was 2022 with 1; the latest was 2022.

Background: when mosquitoes go away for the winter; how the dates are worked out.