Mosquito season in Clinton County, OH: when it starts and ends
Mosquito months in Clinton County
In a normal year mosquito season in Clinton County, OH starts around April 6 and ends around October 28, about 29 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Clinton County, and when
- Start tipping out standing water weekly by March 23.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 28.
- No West Nile cases since 2016, so bites in Clinton County are a nuisance; check window screens.
Clinton County against the rest of OH
Clinton County has the 10th longest season of 88 OH counties, at 205 days against 209 in Gallia County and 177 in Ashtabula County. Its mean temperature is 53.1°F.
- Ross County: April 6 to October 29 (206 days, 3 WNV)
- Warren County: April 6 to October 29 (206 days, 3 WNV)
- Miami County: April 8 to October 28 (203 days, 1 WNV)
- Butler County: April 8 to October 27 (202 days, 3 WNV)
West Nile in Clinton County
From 1999 to 2025, CDC ArboNET counted 5 human West Nile cases in Clinton County (3 neuroinvasive) across 3 years. The worst was 2002 with 3; the latest was 2007.
More: how the dates are worked out · when mosquitoes go away for the winter.