Mercer County Climate
Mercer County, Pennsylvania
Avg Annual Temp
48.5°F
Annual Precip
—
Annual Snowfall
—
Extreme Heat Days
6
days >= 90°F/yr
Monthly Temperature
Precipitation Calendar
Precipitation data coming soon
Seasonal Overview
National Comparison
Data pending
Climate Profile
About Mercer County Weather
Cooler Temps in the Northwest
Mercer County averages 48.5°F, placing it well below the national median temperature. The climate is heavily influenced by its proximity to the Great Lakes, leading to cooler overall conditions.
Below the Pennsylvania Mean
The county sits 1.4 degrees below the state average of 49.9°F. Its location on the western border subjects it to colder air masses moving across the Midwestern plains.
Milder Summers Than Neighbors
With only 6 extreme heat days, Mercer offers a much cooler summer than Lawrence County’s 21 days. While local precipitation data is limited, its temperature patterns suggest a standard humid continental cycle.
Cold Winters and Gentle Summers
January averages a chilly 25.5°F, contributing to a 28.0°F winter average. Summer is mild by comparison, with July temperatures peaking at a comfortable 69.2°F.
Focus on Winter Heating Efficiency
Reliable heating is the priority given the cold 25.5°F January average. While specific snowfall records are limited, residents should prepare for typical Great Lakes winter conditions.
Frequently Asked Questions
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Data source: NOAA National Centers for Environmental Information (NCEI), U.S. Climate Normals 1991-2020.
Climate normals are 30-year averages of weather variables computed from 1991 to 2020. Station data is aggregated to county level using spatial averaging. Data is informational only — not a substitute for official National Weather Service forecasts or emergency weather warnings.