Mosquito season in Berks County, PA: when it starts and ends
Mosquito months in Berks County
In a normal year mosquito season in Berks County, PA starts around April 9 and ends around October 31, about 29 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Berks County, and when
- Start tipping out standing water weekly by March 26.
- Book any yard treatment for early April, ahead of the July peak.
- Repellent can go away after October 31.
- 17 West Nile cases since 2016: you should wear EPA-registered repellent at dusk June to August, and check PA spray notices.
Berks County against the rest of PA
Berks County has the 3rd longest season of 67 PA counties, at 206 days against 222 in Philadelphia County and 154 in Clinton County. Its mean temperature is 53.8°F.
- Philadelphia County: April 1 to November 9 (222 days, 69 WNV)
- Delaware County: April 4 to November 7 (217 days, 24 WNV)
- York County: April 8 to October 30 (205 days, 14 WNV)
- Lancaster County: April 9 to October 29 (204 days, 44 WNV)
West Nile in Berks County
From 1999 to 2025, CDC ArboNET counted 29 human West Nile cases in Berks County (22 neuroinvasive) across 9 years. The worst was 2003 with 9; the latest was 2025.
More: how the dates are worked out · reading the West Nile counts.