Mosquito season in Bucks County, PA: when it starts and ends
Mosquito months in Bucks County
In a normal year mosquito season in Bucks County, PA starts around April 10 and ends around October 31, about 29 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Bucks County, and when
- Start tipping out standing water weekly by March 27.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 31.
- 28 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to August, and check PA spray notices.
Bucks County against the rest of PA
Bucks County has the 6th longest season of 67 PA counties, at 204 days against 222 in Philadelphia County and 154 in Clinton County. Its mean temperature is 53.4°F.
- York County: April 8 to October 30 (205 days, 14 WNV)
- Lancaster County: April 9 to October 29 (204 days, 44 WNV)
- Franklin County: April 8 to October 28 (203 days, 12 WNV)
- Adams County: April 11 to October 27 (200 days, 2 WNV)
West Nile in Bucks County
From 1999 to 2025, CDC ArboNET counted 57 human West Nile cases in Bucks County (40 neuroinvasive) across 16 years. The worst was 2003 with 15; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.