All Countries
Weather & Climate in Mercer, PA
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Mercer experiences four distinct seasons with an average annual temperature of 49°F (9°C). Winters average 26°F in January while summers reach 69°F in July. The area gets 282 sunny days per year, well above the U.S. average of 205 / making it one of the sunnier locations in the country. Air quality is rated Good with a median AQI of 40. 75% of days have good air quality. The city sits at an elevation of 1,257 feet.
Temperature
26°F Jan (-4°C)
69°F Jul (21°C)
| Annual Average | 48.5°F |
| 10% below US avg | |
| January Average | 26°F (-4°C) |
| July Average | 69°F (21°C) |
| Sunny Days | 282 days/yr |
Geography
| Elevation | 1,257 ft (383 m) |
| Area | 0.4 sq mi (1.1 km²) |
| Population Density | 1,592/sq mi |
| Coordinates | 41.2265°N, 80.2363°W |
| Timezone | America/New_York |
| County | Mercer County County |
| Nearest Airport | Venango Regional (FKL) 22 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 40.0 |
| Rating | Good |
| Good Days % | 74.9% |
| Unhealthy Days | 0 |
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 77.7 / 100 |
| Social Vulnerability | 54.8 / 100 |
| Community Resilience | 75.5 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Hurricane | Relatively Low |
| Earthquake | Very Low |
| Wildfire | Very Low |
| Flood | Relatively Moderate |
| Hail | Relatively Moderate |
| Strong Wind | Relatively Moderate |
| Heat Wave | Very Low |
| Winter Weather | Relatively Moderate |
| Lightning | Relatively High |
| Ice Storm | Relatively Low |
| Drought | No Rating |
| Cold Wave | Very Low |
| Landslide | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
36 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.5.
| Sep 25, 1998 | 2 km SW of Adamsville, Pennsylvania | M4.5 | 32 km | 5 km |
| Jun 10, 2019 | 1 km NW of Timberlake, Ohio | M4.0 | 114 km | 2 km |
| Jan 26, 2001 | 8 km NNW of Edgewood, Ohio | M3.9 | 92 km | 5 km |
| Mar 12, 2007 | Ohio | M3.7 | 96 km | 5 km |
| Jun 30, 2003 | 6 km NW of Perry, Ohio | M3.6 | 103 km | 5 km |
| Aug 28, 2023 | 7 km SE of Madison, Ohio | M3.6 | 83 km | 5 km |
| Oct 16, 1993 | 8 km SSE of Madison, Ohio | M3.6 | 83 km | 5 km |
| Jun 20, 2006 | 9 km WNW of North Perry, Ohio | M3.5 | 107 km | 5 km |
| Mar 15, 1992 | 15 km NW of North Perry, Ohio | M3.5 | 113 km | 5 km |
| Jan 26, 1991 | 1 km NNE of Mayfield Heights, Ohio | M3.4 | 107 km | 5 km |
| Jun 3, 2001 | 3 km N of Edgewood, Ohio | M3.4 | 87 km | 5 km |
| Jun 30, 2004 | 2 km WNW of Madison, Ohio | M3.3 | 93 km | 5 km |
| Jul 1, 2013 | 5 km NNW of Fairport Harbor, Ohio | M3.2 | 108 km | 5 km |
| Jan 9, 2008 | 6 km WNW of Mentor-on-the-Lake, Ohio | M3.1 | 114 km | 5 km |
| Mar 11, 2006 | 8 km NNW of Mentor-on-the-Lake, Ohio | M3.1 | 114 km | 5 km |
| Apr 25, 2010 | 2 km WNW of Madison, Ohio | M3.0 | 93 km | 5 km |
| Mar 30, 2024 | 2 km SSW of Maple Ridge, Ohio | M3.0 | 78 km | 6 km |
| Feb 23, 1995 | 3 km W of Ashtabula, Ohio | M2.9 | 87 km | 5 km |
| Aug 7, 2000 | 2 km S of Limaville, Ohio | M2.9 | 82 km | 5 km |
| Jan 4, 2022 | 3 km NW of Timberlake, Ohio | M2.8 | 115 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Tornado History
314 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF5. Total: 74 fatalities, 1,086 injuries.
| Date | Rating | Distance | Path | Fatalities |
| May 31, 1985 | EF5 | 77 km | 47.0 mi | 18 |
| May 31, 1985 | EF4 | 82 km | 28.0 mi | 0 |
| May 31, 1985 | EF4 | 72 km | 14.0 mi | 12 |
| May 31, 1985 | EF4 | 37 km | 56.2 mi | 16 |
| May 31, 1985 | EF4 | 63 km | 29.0 mi | 7 |
| Jun 3, 1980 | EF4 | 77 km | 11.8 mi | 0 |
| May 31, 1985 | EF3 | 68 km | 15.0 mi | 0 |
| May 31, 1985 | EF3 | 49 km | 39.0 mi | 9 |
| May 31, 1985 | EF3 | 81 km | 17.0 mi | 0 |
| May 31, 1985 | EF3 | 53 km | 23.0 mi | 2 |
| May 31, 1985 | EF3 | 66 km | 8.0 mi | 0 |
| Oct 12, 1978 | EF3 | 74 km | 7.3 mi | 0 |
| Jun 3, 1973 | EF3 | 100 km | 12.9 mi | 0 |
| May 2, 1972 | EF3 | 27 km | 7.9 mi | 0 |
| Jun 2, 1971 | EF3 | 72 km | 29.3 mi | 0 |
| Aug 5, 1956 | EF3 | 40 km | 0.1 mi | 2 |
| Mar 1, 1955 | EF3 | 37 km | 2.5 mi | 1 |
| May 7, 2024 | EF2 | 86 km | 15.3 mi | 0 |
| Aug 24, 2023 | EF2 | 77 km | 0.7 mi | 0 |
| Mar 31, 2022 | EF2 | 85 km | 8.6 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Tsunami History
1 tsunami recorded within 500 km. Highest wave on record: 2.7 m (9 ft).
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1823 | LAKE ERIE | Unknown | 2.7 m | - | 134 km |
Source: NOAA/NCEI Historical Tsunami Database.
Wildfire History
2 wildfires (100+ acres) recorded within 100 km. Largest: UNNAMED (628 acres, 1990).
| Year | Name | Acres Burned | Distance |
| 1990 | UNNAMED | 628 | 72 km |
| 2021 | UNNAMED | 586 | 84 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 26°F (-4°C) | 2.4 in | Coldest |
| February | 27°F (-3°C) | 2.1 in | Driest |
| March | 36°F (2°C) | 3.0 in | |
| April | 47°F (8°C) | 3.4 in | |
| May | 57°F (14°C) | 3.7 in | |
| June | 66°F (19°C) | 4.5 in | Wettest |
| July | 69°F (21°C) | 4.3 in | Warmest |
| August | 68°F (20°C) | 3.9 in | |
| September | 62°F (16°C) | 4.0 in | |
| October | 51°F (10°C) | 3.0 in | |
| November | 40°F (5°C) | 3.4 in | |
| December | 30°F (-1°C) | 3.0 in |
Mercer has a seasonal temperature swing of 44°F / from 26°F in January to 69°F in July. Total annual precipitation is 40.6 inches, with June being the wettest month (4.5") and February the driest (2.1").