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Union County Climate

Union County, Pennsylvania

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec51.1°AVG °F

Avg Annual Temp

51.1°F

Annual Precip

43.9"

Annual Snowfall

28.8"

Extreme Heat Days

18

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
3.1"
2.4"
3.5"
3.8"
3.9"
3.7"
4.5"
4.3"
4.4"
3.8"
3.1"
3.4"
Jan
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec

Growing Season & Gardening

USDA Hardiness Zone

6b

Minimum winter temperature range for plant survival

Growing Degree Days

3,042

Supports most vegetables & fruits

Last spring frost (32°F): 04/26
First fall frost (32°F): 10/20

Seasonal Overview

Comfort ZoneSpring38°61°11.2"Summer69°73°12.5"Fall42°64°11.3"Winter28°32°8.9"20°40°60°80°100°

National Comparison

Warmer than 35% of US counties
Wetter than 55% of US counties
More seasonal variation than 64% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Union County

Climate Verdict

Union County has a mild, with an average annual temperature of 51.1°F, moderately wet with 43.9 inches of annual precipitation, rare extreme heat with only 18.4 days above 90°F annually, moderate snowfall of 28.8 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 27.8°F. summers are warm — July averages 73.3°F. The 46°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

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

Regional Context

Union County closely matches the Pennsylvania statewide average temperature of 49.8°F.

Climate Profile

About Union County Weather

Typical Mid-Atlantic Warmth and Humidity

Union County averages 51.1°F annually, which is slightly above the national median. It experiences a humid continental climate with a notable amount of summer heat days.

Warmer Than the Pennsylvania Average

Union’s 51.1°F average temperature exceeds the state average of 49.9°F. It is also one of the drier counties in the state, receiving 43.9 inches of precipitation compared to the 45.3-inch average.

The Warmest in the Immediate Region

Union is slightly warmer than neighboring Snyder County, averaging 51.1°F annually. It also sees the least snow in the local group, with only 28.8 inches per year.

Hot Summers and Brisk, Light Winters

Summer is pronounced here, featuring 18 days above 90°F and a July average of 73.3°F. Winters are relatively mild for the state, with a January average of 27.8°F and under 30 inches of snow.

Invest in High-Efficiency Summer Cooling

With 18 extreme heat days, a well-maintained air conditioning system is vital for comfort and safety. Winter needs are moderate, as the county receives only 28.8 inches of snow, the lowest in this eight-county set.

Frequently Asked Questions

What is the average temperature in Union County?
The average annual temperature in Union County, PA is 51.1°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Union County get?
Union County receives an average of 43.9 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 Union County?
Yes, Union County receives an average of 28.8 inches of snowfall per year according to NOAA climate normals.
How hot does Union County get in summer?
The average summer temperature (June-August) in Union County is 71.3°F. The county experiences an average of 18 days per year above 90°F.
How cold are winters in Union County?
The average winter temperature (December-February) in Union County is 30.1°F. January, typically the coldest month, averages 27.8°F.

Track your own weather in Union 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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