Mosquito season in Forest County, PA: when it starts and ends
Mosquito months in Forest County
In a normal year mosquito season in Forest County, PA starts around May 2 and ends around October 13, about 23 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Forest County, and when
- Start tipping out standing water weekly by April 18.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 13.
- No West Nile cases since 2016, so bites in Forest County are a nuisance; check window screens.
Forest County against the rest of PA
Forest County has the 56th longest season of 67 PA counties, at 164 days against 222 in Philadelphia County and 154 in Clinton County. Its mean temperature is 46.9°F.
- Tioga County: April 30 to October 12 (165 days, 2 WNV)
- Wyoming County: May 1 to October 13 (165 days, 0 WNV)
- Mercer County: May 3 to October 13 (163 days, 0 WNV)
- Cambria County: May 4 to October 12 (161 days, 4 WNV)
West Nile in Forest County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Forest County (1 neuroinvasive) across 1 year. The worst was 2003 with 1; the latest was 2003.
More: how the dates are worked out · when mosquitoes go away for the winter.