Mosquito season in Susquehanna County, PA: when it starts and ends
Mosquito months in Susquehanna County
In a normal year mosquito season in Susquehanna County, PA starts around May 3 and ends around October 9, about 23 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Susquehanna County, and when
- Start tipping out standing water weekly by April 19.
- Book any yard treatment for early May, ahead of the July peak.
- Repellent can go away after October 9.
- No West Nile cases since 2016, so bites in Susquehanna County are a nuisance; check window screens.
Susquehanna County against the rest of PA
Susquehanna County has the 62nd longest season of 67 PA counties, at 159 days against 222 in Philadelphia County and 154 in Clinton County. Its mean temperature is 45.2°F.
- McKean County: May 3 to October 10 (160 days, 0 WNV)
- Wayne County: May 3 to October 10 (160 days, 0 WNV)
- Sullivan County: May 2 to October 8 (158 days, 0 WNV)
- Potter County: May 3 to October 8 (158 days, 1 WNV)
West Nile in Susquehanna County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Susquehanna County (1 neuroinvasive) across 1 year. The worst was 2003 with 1; the latest was 2003.
Background: when the season starts across the US; how the dates are worked out.