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Union County Climate

Union County, New Jersey

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec55.0°AVG °F

Avg Annual Temp

55.0°F

Annual Precip

48.6"

Annual Snowfall

26.4"

Extreme Heat Days

28

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
3.6"
3.1"
4.3"
3.8"
4.1"
4.4"
5.1"
4.1"
4.1"
4.2"
3.5"
4.3"
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

3,747

Supports most vegetables & fruits

Last spring frost (32°F): 04/11
First fall frost (32°F): 10/31

Seasonal Overview

Comfort ZoneSpring42°63°12.2"Summer72°77°13.6"Fall46°69°11.8"Winter33°38°11.0"20°40°60°80°100°

National Comparison

Warmer than 52% of US counties
Wetter than 72% of US counties
More seasonal variation than 59% 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 55.0°F, moderately wet with 48.6 inches of annual precipitation, occasional hot days — 28.46666666666667 per year above 90°F, moderate snowfall of 26.4 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 32.5°F. summers are warm — July averages 77.3°F. The 45°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

The moderate temperatures support hiking, cycling, and camping comfortably in spring, summer, and fall.

Regional Context

Union County closely matches the New Jersey statewide average temperature of 53.6°F.

Climate Profile

About Union County Weather

Warm and Humid Eastern Climate

Union County’s 55.0°F annual average is comfortably above the national median temperature. This area experiences a humid climate with high moisture levels throughout the year.

Consistently Above State Averages

At 55.0°F, Union County is roughly 1.4 degrees warmer than the New Jersey state average of 53.6°F. Its urban density and coastal proximity contribute to these elevated temperature levels.

Hotter and Wetter than Warren

Union records 28 days of extreme heat annually, far outpacing Warren County's 17 days. It also receives 48.6 inches of precipitation, making it one of the more humid corridors in the region.

Steamy Summers and Steady Snow

July is hot with an average of 77.3°F and nearly a month's worth of days exceeding 90°F. Despite the heat, winters still deliver a significant 26.4 inches of snow on average.

Ready for Floods and Heat

Residents should plan for high humidity and 28 days of extreme heat with robust air conditioning. With 48.6 inches of rain and significant snowfall, maintaining clear gutters and sump pumps is vital for property care.

Frequently Asked Questions

What is the average temperature in Union County?
The average annual temperature in Union County, NJ is 55.0°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Union County get?
Union County receives an average of 48.6 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 26.4 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 75.0°F. The county experiences an average of 28 days per year above 90°F.
How cold are winters in Union County?
The average winter temperature (December-February) in Union County is 35.1°F. January, typically the coldest month, averages 32.5°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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