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Chester County Climate

Chester County, Pennsylvania

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec52.9°AVG °F

Avg Annual Temp

52.9°F

Annual Precip

48.8"

Annual Snowfall

28.5"

Extreme Heat Days

19

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
3.6"
3.0"
4.3"
3.8"
3.7"
4.3"
4.5"
4.5"
4.9"
4.4"
3.4"
4.4"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

7a

Minimum winter temperature range for plant survival

Growing Degree Days

3,326

Supports most vegetables & fruits

Last spring frost (32°F): 04/19
First fall frost (32°F): 10/26

Seasonal Overview

Comfort ZoneSpring40°61°11.9"Summer70°75°13.4"Fall44°66°12.7"Winter31°35°10.9"20°40°60°80°100°

National Comparison

Warmer than 43% of US counties
Wetter than 72% of US counties
More seasonal variation than 57% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Chester County

Climate Verdict

Chester County has a mild, with an average annual temperature of 52.9°F, moderately wet with 48.8 inches of annual precipitation, rare extreme heat with only 19.080000000000002 days above 90°F annually, moderate snowfall of 28.5 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 30.5°F. summers are warm — July averages 75.0°F. The 44°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

Growing season and gardening data is currently limited for Chester County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.

Regional Context

Chester County is 3.1°F warmer than the Pennsylvania statewide average of 49.8°F, it is somewhat wetter than average for Pennsylvania.

Climate Profile

About Chester County Weather

A Near National Median Climate

Chester County averages 52.9°F, aligning closely with the national median temperature. This region enjoys the mildest climate profile in the Pennsylvania area.

One of Pennsylvania's Warmest Counties

At 52.9°F, Chester County is significantly warmer than the state average of 49.9°F. It ranks among the top tier of counties for annual heat and mild winters.

Milder Than Neighboring Bucks County

Chester is slightly warmer than its neighbor Bucks County, which averages 52.3°F. It receives 48.8 inches of rain, exceeding the state average of 45.3 inches.

Hot Summers and Manageable Winters

July averages 75.0°F with 19 days of extreme heat reaching 90°F or higher. Winters are mild for Pennsylvania, seeing 28.5 inches of snow and a 32.8°F average.

Prepare for Heat and Moisture

Efficient air conditioning is a necessity to manage nearly 20 days of extreme summer heat. Property owners should also plan for heavy rain given the 48.8-inch annual precipitation.

Frequently Asked Questions

What is the average temperature in Chester County?
The average annual temperature in Chester County, PA is 52.9°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Chester County get?
Chester County receives an average of 48.8 inches of precipitation per year, including both rain and meltwater from snow. This is based on NOAA 30-year climate normals.
Does it snow in Chester County?
Yes, Chester County receives an average of 28.5 inches of snowfall per year according to NOAA climate normals.
How hot does Chester County get in summer?
The average summer temperature (June-August) in Chester County is 72.8°F. The county experiences an average of 19 days per year above 90°F.
How cold are winters in Chester County?
The average winter temperature (December-February) in Chester County is 32.8°F. January, typically the coldest month, averages 30.5°F.

Track your own weather in Chester County

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Data sources: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020. Forecast and alert data from National Weather Service API. Air quality data from Open-Meteo.

Climate normals are 30-year averages of weather variables. Station data is aggregated to county level. Forecasts and alerts are fetched live and may change frequently. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.

By Evan Brooks, Data EditorUpdated Reviewed by Evan Brooks, Data Editor
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