Currently: 75 °F. Partly cloudy. (Weather station: Lancaster Airport, USA). See more current weatherAnnual Weather Averages in Lancaster Airport
Lancaster Airport is 31 miles from Chester County, so the actual climate in Chester County can vary a bit.
Based on weather reports collected during 1992–2021.
All Year Climate & Weather Averages in Chester County
High Temp: 85 °F
Low Temp: 23 °F
Mean Temp: 53 °F
Precipitation: 3.18"
Humidity: 68%
Dew Point: 43 °F
Wind: 12 mph
Pressure: 30.05 "Hg
Visibility: 9 mi
January Climate & Weather Averages in Chester County
High Temp: 38 °F
Low Temp: 23 °F
Mean Temp: 31 °F
Precipitation: 2.25"
Humidity: 68%
Dew Point: 21 °F
Wind: 14 mph
Pressure: 30.10 "Hg
Visibility: 9 mi
February Climate & Weather Averages in Chester County
High Temp: 41 °F
Low Temp: 25 °F
Mean Temp: 33 °F
Precipitation: 2.20"
Humidity: 65%
Dew Point: 22 °F
Wind: 14 mph
Pressure: 30.08 "Hg
Visibility: 9 mi
March Climate & Weather Averages in Chester County
High Temp: 50 °F
Low Temp: 31 °F
Mean Temp: 41 °F
Precipitation: 2.88"
Humidity: 62%
Dew Point: 28 °F
Wind: 15 mph
Pressure: 30.07 "Hg
Visibility: 10 mi
April Climate & Weather Averages in Chester County
High Temp: 62 °F
Low Temp: 41 °F
Mean Temp: 52 °F
Precipitation: 3.00"
Humidity: 61%
Dew Point: 38 °F
Wind: 14 mph
Pressure: 30.00 "Hg
Visibility: 10 mi
May Climate & Weather Averages in Chester County
High Temp: 72 °F
Low Temp: 51 °F
Mean Temp: 62 °F
Precipitation: 3.06"
Humidity: 67%
Dew Point: 50 °F
Wind: 12 mph
Pressure: 30.01 "Hg
Visibility: 9 mi
June Climate & Weather Averages in Chester County
High Temp: 81 °F
Low Temp: 61 °F
Mean Temp: 71 °F
Precipitation: 3.85"
Humidity: 68%
Dew Point: 60 °F
Wind: 11 mph
Pressure: 29.97 "Hg
Visibility: 9 mi
July Climate & Weather Averages in Chester County
High Temp: 85 °F
Low Temp: 66 °F
Mean Temp: 75 °F
Precipitation: 3.86"
Humidity: 70%
Dew Point: 65 °F
Wind: 10 mph
Pressure: 29.98 "Hg
Visibility: 8 mi
August Climate & Weather Averages in Chester County
High Temp: 84 °F
Low Temp: 64 °F
Mean Temp: 74 °F
Precipitation: 3.43"
Humidity: 72%
Dew Point: 64 °F
Wind: 8 mph
Pressure: 30.02 "Hg
Visibility: 8 mi
September Climate & Weather Averages in Chester County
High Temp: 77 °F
Low Temp: 57 °F
Mean Temp: 67 °F
Precipitation: 4.44"
Humidity: 72%
Dew Point: 57 °F
Wind: 9 mph
Pressure: 30.06 "Hg
Visibility: 9 mi
October Climate & Weather Averages in Chester County
High Temp: 65 °F
Low Temp: 45 °F
Mean Temp: 55 °F
Precipitation: 3.71"
Humidity: 72%
Dew Point: 46 °F
Wind: 11 mph
Pressure: 30.08 "Hg
Visibility: 9 mi
November Climate & Weather Averages in Chester County
High Temp: 53 °F
Low Temp: 35 °F
Mean Temp: 44 °F
Precipitation: 2.61"
Humidity: 69%
Dew Point: 34 °F
Wind: 12 mph
Pressure: 30.13 "Hg
Visibility: 10 mi
December Climate & Weather Averages in Chester County
High Temp: 43 °F
Low Temp: 28 °F
Mean Temp: 36 °F
Precipitation: 2.89"
Humidity: 71%
Dew Point: 27 °F
Wind: 13 mph
Pressure: 30.11 "Hg
Visibility: 9 mi