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Weather & Climate in Pennwyn, PA
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Pennwyn experiences four distinct seasons with an average annual temperature of 54°F (12°C). Winters average 31°F in January while summers reach 76°F in July. The area gets 275 sunny days per year, well above the U.S. average of 205 / making it one of the sunnier locations in the country. Annual precipitation totals 45.2 inches. Air quality is rated Good with a median AQI of 40. The city sits at an elevation of 410 feet.
Temperature
31°F Jan (-1°C)
76°F Jul (25°C)
| Annual Average | 53.7°F |
| 1% below US avg | |
| January Average | 31°F (-1°C) |
| July Average | 76°F (25°C) |
| Sunny Days | 275 days/yr |
Geography
| Elevation | 410 ft (125 m) |
| Area | 0.5 sq mi (1.4 km²) |
| Population Density | 909/sq mi |
| Coordinates | 40.2890°N, 75.9736°W |
| Timezone | America/New_York |
| County | Berks County County |
| Nearest Airport | Reading Regional/Carl A Spaatz Field (RDG) 6 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 40.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 92.7 / 100 |
| Social Vulnerability | 48.5 / 100 |
| Community Resilience | 85.6 / 100 |
Hazard Breakdown
| Tornado | Relatively High |
| Hurricane | Relatively Moderate |
| Earthquake | Relatively Moderate |
| Wildfire | Very Low |
| Flood | Relatively High |
| Hail | Relatively Low |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Very High |
| Lightning | Relatively High |
| Ice Storm | Relatively Moderate |
| Drought | Relatively High |
| Cold Wave | Relatively High |
| Landslide | Relatively Moderate |
| Avalanche | 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: M4.8.
| Apr 5, 2024 | 2024 Tewksbury, New Jersey Earthquake | M4.8 | 112 km | 3 km |
| Jan 16, 1994 | 2 km W of Sinking Spring, Pennsylvania | M4.6 | 7 km | 5 km |
| Jan 16, 1994 | 0 km E of Sinking Spring, Pennsylvania | M4.2 | 5 km | 5 km |
| Apr 5, 2024 | 7 km WSW of Gladstone, New Jersey | M3.7 | 113 km | 4 km |
| Jun 13, 2019 | 9 km N of Blain, Pennsylvania | M3.4 | 131 km | 27 km |
| Oct 23, 1990 | 3 km W of Hancocks Bridge, New Jersey | M3.2 | 95 km | 10 km |
| Aug 26, 2003 | 4 km NNW of Milford, New Jersey | M3.1 | 82 km | 3 km |
| Jan 9, 1992 | 4 km WNW of Robertsville, New Jersey | M3.1 | 139 km | 8 km |
| Jun 3, 2010 | 4 km ENE of Franklintown, Pennsylvania | M3.1 | 88 km | 2 km |
| Nov 14, 1997 | 0 km S of Rothsville, Pennsylvania | M3.0 | 29 km | 5 km |
| Feb 3, 2009 | 1 km ESE of Victory Gardens, New Jersey | M3.0 | 138 km | 0 km |
| Apr 24, 2009 | 1 km S of Franklintown, Pennsylvania | M2.9 | 93 km | 1 km |
| Apr 27, 2024 | 7 km WSW of Gladstone, New Jersey | M2.9 | 113 km | 5 km |
| May 24, 2024 | 6 km E of Califon, New Jersey | M2.9 | 113 km | 7 km |
| Jan 16, 1994 | 0 km SSE of Sinking Spring, Pennsylvania | M2.9 | 5 km | 5 km |
| Sep 15, 2019 | 5 km ESE of East Berlin, Pennsylvania | M2.8 | 90 km | 5 km |
| May 10, 1993 | 1 km NW of Whitfield, Pennsylvania | M2.8 | 8 km | 5 km |
| Jul 1, 2009 | 3 km ESE of Pennsville, New Jersey | M2.8 | 83 km | 5 km |
| Oct 25, 2009 | 4 km ENE of Franklintown, Pennsylvania | M2.8 | 88 km | 1 km |
| Oct 28, 1994 | 1 km E of Mount Vernon, Maryland | M2.7 | 122 km | — |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Hurricane History
3 hurricanes (Category 1+) recorded within 500 km since 1980. Strongest on record: Category 2.
| Year | Name | Category | Max Wind | Closest |
| 2011 | Irene | Category 1 | 75 mph | 258 km |
| 1991 | Bob | Category 3 | 109 mph | 298 km |
| 1985 | Gloria | Category 2 | 98 mph | 204 km |
Source: NOAA IBTrACS (Category 1+, 1980–2026).
Tornado History
408 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF3. Total: 9 fatalities, 295 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Sep 1, 2021 | EF3 | 92 km | 12.4 mi | 0 |
| Jul 29, 2021 | EF3 | 84 km | 3.4 mi | 0 |
| Jul 14, 2004 | EF3 | 51 km | 7.5 mi | 0 |
| May 31, 1998 | EF3 | 22 km | 8.3 mi | 0 |
| Jul 27, 1994 | EF3 | 39 km | 2.0 mi | 3 |
| Jul 27, 1994 | EF3 | 64 km | 4.0 mi | 0 |
| Jul 26, 1981 | EF3 | 63 km | 3.3 mi | 0 |
| Jun 7, 1980 | EF3 | 98 km | 1.5 mi | 0 |
| Jun 18, 1970 | EF3 | 30 km | 1.9 mi | 1 |
| Apr 28, 1961 | EF3 | 77 km | 0.3 mi | 0 |
| Mar 22, 1955 | EF3 | 47 km | 9.6 mi | 1 |
| Nov 4, 1950 | EF3 | 16 km | 15.9 mi | 0 |
| Sep 1, 2021 | EF2 | 58 km | 5.9 mi | 0 |
| Sep 1, 2021 | EF2 | 66 km | 8.3 mi | 1 |
| Jul 29, 2021 | EF2 | 87 km | 6.3 mi | 0 |
| Aug 4, 2020 | EF2 | 89 km | 20.8 mi | 0 |
| Oct 31, 2019 | EF2 | 57 km | 0.5 mi | 0 |
| May 28, 2019 | EF2 | 15 km | 3.1 mi | 0 |
| Feb 24, 2016 | EF2 | 31 km | 4.9 mi | 0 |
| Apr 28, 2011 | EF2 | 83 km | 2.6 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Tsunami History
2 tsunamis recorded within 500 km.
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1895 | HIGH BRIDGE, NJ | Earthquake | — | — | 101 km |
| 1840 | PHILADELPHIA, PENNSYLVANIA | Earthquake | — | — | 85 km |
Source: NOAA/NCEI Historical Tsunami Database.
Wildfire History
4 wildfires (100+ acres) recorded within 100 km. Largest: CRYSTAL LAKE (1,838 acres, 2004).
| Year | Name | Acres Burned | Distance |
| 2004 | CRYSTAL LAKE | 1,838 | 98 km |
| 2012 | HOPEWELL FIRE | 812 | 21 km |
| 2015 | RAZOR FIRE | 728 | 60 km |
| 2015 | PIPELINE 1 | 666 | 96 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 31°F (-1°C) | 3.4 in | |
| February | 31°F (-1°C) | 2.8 in | Coldest, Driest |
| March | 40°F (4°C) | 3.5 in | |
| April | 50°F (10°C) | 3.7 in | |
| May | 60°F (16°C) | 4.4 in | Wettest |
| June | 69°F (20°C) | 4.3 in | |
| July | 76°F (25°C) | 4.3 in | Warmest |
| August | 72°F (22°C) | 3.9 in | |
| September | 65°F (19°C) | 4.1 in | |
| October | 54°F (12°C) | 3.3 in | |
| November | 44°F (7°C) | 3.8 in | |
| December | 34°F (1°C) | 3.5 in |
Pennwyn has a seasonal temperature swing of 46°F / from 31°F in February to 76°F in July. Total annual precipitation is 45.0 inches, with May being the wettest month (4.4") and February the driest (2.8").