Mosquito season in Erie County, PA: when it starts and ends
Mosquito months in Erie County
In a normal year mosquito season in Erie County, PA starts around April 22 and ends around October 27, about 27 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Erie County, and when
- Start tipping out standing water weekly by April 8.
- Book any yard treatment for late April, ahead of the July peak.
- Repellent can go away after October 27.
- 1 West Nile case since 2016 (last 2018): you should use repellent at dusk July to August, more so if over 60.
Erie County against the rest of PA
Erie County has the 28th longest season of 67 PA counties, at 188 days against 222 in Philadelphia County and 154 in Clinton County. Its mean temperature is 50.7°F.
- Dauphin County: April 18 to October 23 (188 days, 8 WNV)
- Lawrence County: April 20 to October 25 (188 days, 2 WNV)
- Bedford County: April 16 to October 20 (187 days, 1 WNV)
- Montour County: April 17 to October 21 (187 days, 1 WNV)
West Nile in Erie County
From 1999 to 2025, CDC ArboNET counted 10 human West Nile cases in Erie County (6 neuroinvasive) across 6 years. The worst was 2002 with 4; the latest was 2018.
See how the dates are worked out, and when mosquitoes go away for the winter.