Jefferson County Climate
Jefferson County, Pennsylvania
NOAA NCEI 1991-2020 Climate NormalsAvg Annual Temp
47.7°F
Annual Precip
42.4"
Annual Snowfall
—
Extreme Heat Days
2
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Growing Season & Gardening
6a
Minimum winter temperature range for plant survival
2,428
Favors cool-season crops
Seasonal Overview
National Comparison
7-Day Outlook
Forecast
Current Conditions
Air Quality
Safety
Weather Alerts
Climate Advisory: Jefferson County
Climate Verdict
Jefferson County has a cool, averaging 47.7°F annually, moderately wet with 42.4 inches of annual precipitation, rare extreme heat with only 1.6 days above 90°F annually. This climate profile shapes everything from energy costs to outdoor recreation opportunities.
Seasonal Breakdown
Winters are very cold — January averages 24.5°F. summers are pleasantly cool with July averaging 69.1°F. The 45°F seasonal variation provides noticeable but manageable change.
Outdoor & Gardening Guidance
Growing season and gardening data is currently limited for Jefferson County. Check the USDA Plant Hardiness Zone Map and local extension office for specific guidance.
Regional Context
Jefferson County closely matches the Pennsylvania statewide average temperature of 49.8°F, it is somewhat drier than average for Pennsylvania.
Climate Profile
About Jefferson County Weather
The Region's Coldest County
Jefferson County is the coldest in this set with a 47.7°F annual average. This reflects a rugged continental climate with significantly more cold days than its neighbors.
Chillier Than the State Average
It sits 2.2 degrees below the Pennsylvania state average of 49.9°F. Annual precipitation is also slightly lower than the state mean, totaling 42.4 inches.
The Regional Icebox
Jefferson is the coldest county among its peers, averaging 4.3 degrees lower than Huntingdon. While other counties face many hot days, Jefferson only sees 2 days above 90°F.
Long Winters, Very Cool Summers
Winter is long with January averages dipping to 24.5°F. Summer is exceptionally cool, with a July average of 69.1°F and almost no extreme heat recorded.
Focus on Winter Heating
Prioritize home heating efficiency and cold-weather vehicle preparation for the sustained freeze. Extreme heat is rare, so homeowners should focus on insulation over high-powered cooling.
Frequently Asked Questions
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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.