Mosquito season in Snyder County, PA: when it starts and ends
Mosquito months in Snyder County
In a normal year mosquito season in Snyder County, PA starts around April 14 and ends around October 23, about 28 weeks.
- Jan
- Feb
- Mar
- Apr
- May
- Jun
- Jul
- Aug
- Sep
- Oct
- Nov
- Dec
What to do in Snyder County, and when
- Start tipping out standing water weekly by March 31.
- Book any yard treatment for mid April, ahead of the July peak.
- Repellent can go away after October 23.
- No West Nile cases since 2016, so bites in Snyder County are a nuisance; check window screens.
Snyder County against the rest of PA
Snyder County has the 21st longest season of 67 PA counties, at 193 days against 222 in Philadelphia County and 154 in Clinton County. Its mean temperature is 51.3°F.
- Huntingdon County: April 14 to October 26 (195 days, 1 WNV)
- Perry County: April 14 to October 26 (195 days, 1 WNV)
- Union County: April 15 to October 23 (191 days, 1 WNV)
- Mifflin County: April 16 to October 22 (190 days, 0 WNV)
West Nile in Snyder County
From 1999 to 2025, CDC ArboNET counted 1 human West Nile case in Snyder County (1 neuroinvasive) across 1 year. The worst was 2003 with 1; the latest was 2003.
See how the dates are worked out, and when mosquitoes go away for the winter.