Mosquito season in Clearfield County, PA: when it starts and ends
Mosquito months in Clearfield County
In a normal year mosquito season in Clearfield County, PA starts around April 23 and ends around October 15, about 25 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Clearfield County, and when
- Start tipping out standing water weekly by April 9.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 15.
- No West Nile cases since 2016, so bites in Clearfield County are a nuisance; check window screens.
Clearfield County against the rest of PA
Clearfield County has the 44th longest season of 67 PA counties, at 175 days against 222 in Philadelphia County and 154 in Clinton County. Its mean temperature is 48.1°F.
- Crawford County: April 23 to October 18 (177 days, 0 WNV)
- Bradford County: April 24 to October 17 (176 days, 0 WNV)
- Indiana County: April 27 to October 19 (175 days, 1 WNV)
- Butler County: April 26 to October 17 (174 days, 1 WNV)
West Nile in Clearfield County
From 1999 to 2025, CDC ArboNET counted 12 human West Nile cases in Clearfield County (4 neuroinvasive) across 2 years. The worst was 2003 with 10; the latest was 2007.
More: how the dates are worked out · when mosquitoes go away for the winter.