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Allegheny County Climate

Allegheny County, Pennsylvania

NOAA NCEI 1991-2020 Climate Normals
JanFebMarAprMayJunJulAugSepOctNovDec51.9°AVG °F

Avg Annual Temp

51.9°F

Annual Precip

40.9"

Annual Snowfall

32.0"

Extreme Heat Days

15

days >= 90°F/yr

Monthly Temperature

54.4°F avgJFMAMJJASOND

Precipitation Calendar

Dry
Wet= snowfall
3.1"
2.7"
3.3"
3.5"
3.8"
4.4"
4.0"
3.5"
3.6"
3.0"
3.0"
3.1"
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

3,194

Supports most vegetables & fruits

Last spring frost (32°F): 04/18
First fall frost (32°F): 11/01

Seasonal Overview

Comfort ZoneSpring39°61°10.6"Summer69°74°11.9"Fall43°65°9.5"Winter29°34°8.9"20°40°60°80°100°

National Comparison

Warmer than 39% of US counties
Wetter than 48% of US counties
More seasonal variation than 58% of US counties

7-Day Outlook

Forecast

Current Conditions

Air Quality

Safety

Weather Alerts

Climate Advisory: Allegheny County

Climate Verdict

Allegheny County has a mild, with an average annual temperature of 51.9°F, moderately wet with 40.9 inches of annual precipitation, rare extreme heat with only 15.012500000000001 days above 90°F annually, moderate snowfall of 32.0 inches annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.

Seasonal Breakdown

Winters are cold, with January averaging 29.0°F. summers are warm — July averages 73.6°F. The 45°F seasonal variation provides noticeable but manageable change.

Outdoor & Gardening Guidance

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

Regional Context

Allegheny County closely matches the Pennsylvania statewide average temperature of 49.8°F, it is somewhat drier than average for Pennsylvania.

Climate Profile

About Allegheny County Weather

Moderate temperatures in the Steel City

Allegheny County averages 51.9°F annually, placing it slightly below the national median temperature for the United States. The region experiences 40.9 inches of annual precipitation, which is lower than many other coastal or lakeside regions. This climate provides a balanced mix of seasonal variety without the extremes found in the deep south or far north.

Warmer than the Pennsylvania average

At 51.9°F, Allegheny County is two degrees warmer than the Pennsylvania state average of 49.9°F. While it is warmer than the state norm, it remains drier, receiving roughly 4.4 inches less rain and snow than the state average of 45.3 inches. This positioning makes it one of the more temperate major population centers in the Commonwealth.

A urban heat island in Western PA

Allegheny is warmer than adjacent Armstrong and Beaver counties, likely due to the urban heat island effect from Pittsburgh. Its 51.9°F annual average contrasts with Armstrong’s cooler 50.0°F average. However, the county receives less snow than its northern neighbors, making winter travel slightly more predictable.

Steamy July days and snowy winters

July brings an average of 73.6°F with approximately 15 days exceeding 90°F each year. Winter holds its own with 32 inches of annual snowfall and a January average that dips to 29.0°F. The seasonal swing is significant, with nearly 45 degrees of difference between the coldest and warmest months.

Balance salt supplies with cooling needs

Residents should plan for 32 inches of snow by keeping salt and shovels ready for the winter months. Because summer extreme heat days are frequent, central air conditioning is a vital utility for the 15 days of 90°F weather. Proper insulation helps manage the wide 31.4°F to 71.7°F seasonal temperature range.

Frequently Asked Questions

What is the average temperature in Allegheny County?
The average annual temperature in Allegheny County, PA is 51.9°F, based on NOAA 30-year climate normals (1991-2020).
How much rain does Allegheny County get?
Allegheny County receives an average of 40.9 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 Allegheny County?
Yes, Allegheny County receives an average of 32.0 inches of snowfall per year according to NOAA climate normals.
How hot does Allegheny County get in summer?
The average summer temperature (June-August) in Allegheny County is 71.7°F. The county experiences an average of 15 days per year above 90°F.
How cold are winters in Allegheny County?
The average winter temperature (December-February) in Allegheny County is 31.4°F. January, typically the coldest month, averages 29.0°F.

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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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