Mosquito season in Jackson County, OH: when it starts and ends

Mosquito months in Jackson County

In a normal year mosquito season in Jackson County, OH starts around April 9 and ends around October 24, 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 Jackson County, and when

• Start tipping out standing water weekly by March 26.
• Book any yard treatment for early April, ahead of the July peak.
• Repellent can go away after October 24.
• No West Nile cases since 2016, so bites in Jackson County are a nuisance; check window screens.

Jackson County against the rest of OH

Jackson County has the 18th longest season of 88 OH counties, at 198 days against 209 in Gallia County and 177 in Ashtabula County. Its mean temperature is 52°F.

• Clermont County: April 11 to October 27 (199 days, 6 WNV)
• Hancock County: April 12 to October 27 (199 days, 4 WNV)
• Union County: April 10 to October 26 (198 days, 0 WNV)
• Athens County: April 11 to October 26 (198 days, 1 WNV)

West Nile in Jackson County

From 1999 to 2025, CDC ArboNET counted 2 human West Nile cases in Jackson County (2 neuroinvasive) across 2 years. The worst was 2003 with 1; the latest was 2003.

More: how the dates are worked out · when mosquitoes go away for the winter.