All Countries
Weather & Climate in Mount Joy, PA
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Mount Joy experiences four distinct seasons with an average annual temperature of 54°F (12°C). Winters average 31°F in January while summers reach 77°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 44.2 inches. The area receives 29.9 inches of snow annually, a moderate snowfall amount. Air quality is rated Good with a median AQI of 40. The city sits at an elevation of 388 feet.
Temperature
31°F Jan (-1°C)
77°F Jul (25°C)
| Annual Average | 54.3°F |
| 1% above US avg | |
| January Average | 31°F (-1°C) |
| July Average | 77°F (25°C) |
| Sunny Days | 275 days/yr |
Geography
| Elevation | 388 ft (118 m) |
| Area | 0.9 sq mi (2.4 km²) |
| Population Density | 3,448/sq mi |
| Coordinates | 40.1106°N, 76.5057°W |
| Timezone | America/New_York |
| County | Lancaster County County |
| Nearest Airport | Harrisburg International (MDT) 15 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 40.0 |
| Rating | Good |
Natural Hazard Risk
| Overall Risk | Relatively High |
| Risk Score | 95.0 / 100 |
| Social Vulnerability | 43.5 / 100 |
| Community Resilience | 70.1 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Relatively High |
| Earthquake | Relatively Moderate |
| Wildfire | Very Low |
| Flood | Relatively High |
| Hail | Relatively Moderate |
| Strong Wind | Relatively High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Very High |
| Lightning | Relatively High |
| Ice Storm | Relatively Moderate |
| Drought | Relatively Moderate |
| Cold Wave | Relatively High |
| Landslide | Relatively Low |
| Avalanche | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
28 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M4.6.
| Jan 16, 1994 | 2 km W of Sinking Spring, Pennsylvania | M4.6 | 47 km | 5 km |
| Jan 16, 1994 | 0 km E of Sinking Spring, Pennsylvania | M4.2 | 49 km | 5 km |
| Jul 16, 2010 | 5 km NNW of Barnesville, Maryland | M3.6 | 122 km | 7 km |
| Jun 13, 2019 | 9 km N of Blain, Pennsylvania | M3.4 | 92 km | 27 km |
| Oct 23, 1990 | 3 km W of Hancocks Bridge, New Jersey | M3.2 | 108 km | 10 km |
| Aug 26, 2003 | 4 km NNW of Milford, New Jersey | M3.1 | 131 km | 3 km |
| Jun 3, 2010 | 4 km ENE of Franklintown, Pennsylvania | M3.1 | 40 km | 2 km |
| Jan 17, 2016 | 3 km NE of Ranson, West Virginia | M3.0 | 143 km | 5 km |
| Nov 14, 1997 | 0 km S of Rothsville, Pennsylvania | M3.0 | 22 km | 5 km |
| Apr 24, 2009 | 1 km S of Franklintown, Pennsylvania | M2.9 | 45 km | 1 km |
| Jan 16, 1994 | 0 km SSE of Sinking Spring, Pennsylvania | M2.9 | 48 km | 5 km |
| Sep 15, 2019 | 5 km ESE of East Berlin, Pennsylvania | M2.8 | 40 km | 5 km |
| May 10, 1993 | 1 km NW of Whitfield, Pennsylvania | M2.8 | 49 km | 5 km |
| Jul 1, 2009 | 3 km ESE of Pennsville, New Jersey | M2.8 | 102 km | 5 km |
| Oct 25, 2009 | 4 km ENE of Franklintown, Pennsylvania | M2.8 | 40 km | 1 km |
| Mar 15, 1993 | 5 km W of Columbia, Maryland | M2.7 | 103 km | 5 km |
| Oct 28, 1994 | 1 km E of Mount Vernon, Maryland | M2.7 | 91 km | — |
| Mar 11, 1995 | 0 km ENE of Landisville, Pennsylvania | M2.7 | 9 km | 5 km |
| Jan 25, 2015 | 4 km ESE of Downingtown, Pennsylvania | M2.6 | 73 km | 2 km |
| Jan 18, 1994 | 3 km SE of Clay, Pennsylvania | M2.6 | 26 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990–2025). Sorted by magnitude.
Hurricane History
2 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 | 259 km |
| 1985 | Gloria | Category 2 | 98 mph | 248 km |
Source: NOAA IBTrACS (Category 1+, 1980–2026).
Tornado History
411 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF3. Total: 10 fatalities, 293 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Jul 14, 2004 | EF3 | 20 km | 7.5 mi | 0 |
| May 31, 1998 | EF3 | 66 km | 8.3 mi | 0 |
| Jul 19, 1996 | EF3 | 79 km | 2.2 mi | 0 |
| Jul 27, 1994 | EF3 | 75 km | 4.0 mi | 0 |
| Jul 27, 1994 | EF3 | 85 km | 2.0 mi | 3 |
| May 22, 1983 | EF3 | 78 km | 2.0 mi | 0 |
| Jun 7, 1980 | EF3 | 48 km | 1.5 mi | 0 |
| Jun 18, 1970 | EF3 | 37 km | 1.9 mi | 1 |
| Apr 28, 1961 | EF3 | 94 km | 0.3 mi | 0 |
| Apr 16, 1961 | EF3 | 87 km | 0.1 mi | 0 |
| Mar 22, 1955 | EF3 | 77 km | 9.6 mi | 1 |
| Apr 5, 1952 | EF3 | 53 km | 17.5 mi | 0 |
| Nov 4, 1950 | EF3 | 34 km | 15.9 mi | 0 |
| Sep 1, 2021 | EF2 | 59 km | 5.9 mi | 0 |
| Oct 31, 2019 | EF2 | 87 km | 0.5 mi | 0 |
| May 28, 2019 | EF2 | 51 km | 3.1 mi | 0 |
| Feb 24, 2016 | EF2 | 42 km | 4.9 mi | 0 |
| May 23, 2011 | EF2 | 84 km | 4.7 mi | 0 |
| Apr 28, 2011 | EF2 | 36 km | 2.6 mi | 0 |
| Apr 28, 2011 | EF2 | 33 km | 1.1 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950–2024, US only).
Tsunami History
1 tsunami recorded within 500 km.
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1840 | PHILADELPHIA, PENNSYLVANIA | Earthquake | — | — | 117 km |
Source: NOAA/NCEI Historical Tsunami Database.
Wildfire History
1 wildfire (100+ acres) recorded within 100 km. Largest: HOPEWELL FIRE (812 acres, 2012).
| Year | Name | Acres Burned | Distance |
| 2012 | HOPEWELL FIRE | 812 | 65 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 31°F (-1°C) | 3.0 in | Coldest |
| February | 31°F (-0°C) | 2.6 in | Driest |
| March | 40°F (5°C) | 3.2 in | |
| April | 51°F (10°C) | 3.5 in | |
| May | 61°F (16°C) | 4.2 in | |
| June | 70°F (21°C) | 4.1 in | |
| July | 77°F (25°C) | 4.3 in | Warmest, Wettest |
| August | 73°F (23°C) | 3.4 in | |
| September | 66°F (19°C) | 3.7 in | |
| October | 54°F (12°C) | 3.0 in | |
| November | 44°F (7°C) | 3.5 in | |
| December | 35°F (2°C) | 3.2 in |
Mount Joy has a seasonal temperature swing of 47°F / from 31°F in January to 77°F in July. Total annual precipitation is 41.7 inches, with July being the wettest month (4.3") and February the driest (2.6").