Weather & Climate in Duncannon, PA
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Duncannon experiences four distinct seasons with an average annual temperature of 55°F (13°C). Winters average 33°F in January while summers reach 78°F in July. Annual precipitation totals 41.0 inches. The area receives 23.9 inches of snow annually, a moderate snowfall amount. The city sits at an elevation of 365 feet.
Temperature
33°F Jan (0°C)
78°F Jul (25°C)
| Annual Average | 55.2°F |
| 2% above US avg | |
| January Average | 33°F (0°C) |
| July Average | 78°F (25°C) |
Geography
| Elevation | 365 ft (111 m) |
| Area | 0.2 sq mi (0.4 km²) |
| Population Density | 3,185/sq mi |
| Coordinates | 40.3952°N, 77.0277°W |
| Timezone | America/New_York |
| County | Perry County County |
| Nearest Airport | Harrisburg International (MDT) 20 miles away |
Precipitation & Snow
Air Quality
Natural Hazard Risk
| Overall Risk | Relatively Low |
| Risk Score | 53.1 / 100 |
| Social Vulnerability | 33.6 / 100 |
| Community Resilience | 67.8 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Hurricane | Relatively Low |
| Earthquake | Very Low |
| Wildfire | Very Low |
| Flood | Relatively Low |
| Hail | Very Low |
| Strong Wind | Relatively Moderate |
| Heat Wave | Relatively Low |
| Winter Weather | Relatively Moderate |
| Lightning | Relatively Low |
| Ice Storm | Very Low |
| Drought | Very Low |
| Cold Wave | Very Low |
| Landslide | Relatively Low |
| Avalanche | Very Low |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
25 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 | 84 km | 5 km |
| Jan 16, 1994 | 0 km E of Sinking Spring, Pennsylvania | M4.2 | 87 km | 5 km |
| Jul 16, 2010 | 5 km NNW of Barnesville, Maryland | M3.6 | 130 km | 7 km |
| Jun 13, 2019 | 9 km N of Blain, Pennsylvania | M3.4 | 41 km | 27 km |
| Jun 3, 2010 | 4 km ENE of Franklintown, Pennsylvania | M3.1 | 35 km | 2 km |
| Jan 17, 2016 | 3 km NE of Ranson, West Virginia | M3.0 | 138 km | 5 km |
| Nov 14, 1997 | 0 km S of Rothsville, Pennsylvania | M3.0 | 71 km | 5 km |
| Apr 24, 2009 | 1 km S of Franklintown, Pennsylvania | M2.9 | 37 km | 1 km |
| Jan 16, 1994 | 0 km SSE of Sinking Spring, Pennsylvania | M2.9 | 87 km | 5 km |
| Sep 15, 2019 | 5 km ESE of East Berlin, Pennsylvania | M2.8 | 53 km | 5 km |
| Jun 10, 2025 | 10 km NW of Forksville, Pennsylvania | M2.8 | 133 km | 8 km |
| May 10, 1993 | 1 km NW of Whitfield, Pennsylvania | M2.8 | 86 km | 5 km |
| Oct 25, 2009 | 4 km ENE of Franklintown, Pennsylvania | M2.8 | 34 km | 1 km |
| Mar 15, 1993 | 5 km W of Columbia, Maryland | M2.7 | 130 km | 5 km |
| Oct 28, 1994 | 1 km E of Mount Vernon, Maryland | M2.7 | 127 km | - |
| Mar 11, 1995 | 0 km ENE of Landisville, Pennsylvania | M2.7 | 63 km | 5 km |
| Jan 25, 2015 | 4 km ESE of Downingtown, Pennsylvania | M2.6 | 124 km | 2 km |
| Jan 13, 1990 | 6 km ENE of Eldersburg, Maryland | M2.6 | 109 km | 5 km |
| Jun 25, 2021 | 2 km SE of Woodlawn, Maryland | M2.6 | 124 km | 3 km |
| Jan 18, 1994 | 3 km SE of Clay, Pennsylvania | M2.6 | 72 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Hurricane History
1 hurricane (Category 1+) recorded within 500 km since 1980. Strongest on record: Category 1.
| Year | Name | Category | Max Wind | Closest |
| 1985 | Gloria | Category 2 | 98 mph | 294 km |
Source: NOAA IBTrACS (Category 1+, 1980-2026).
Tornado History
317 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF3. Total: 8 fatalities, 180 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Jul 14, 2004 | EF3 | 40 km | 7.5 mi | 0 |
| May 31, 1998 | EF3 | 96 km | 8.3 mi | 0 |
| Jul 19, 1996 | EF3 | 100 km | 2.2 mi | 0 |
| May 31, 1985 | EF3 | 88 km | 19.0 mi | 6 |
| May 22, 1983 | EF3 | 80 km | 2.0 mi | 0 |
| Jun 7, 1980 | EF3 | 52 km | 1.5 mi | 0 |
| Jul 29, 1976 | EF3 | 92 km | 25.0 mi | 0 |
| Jun 18, 1970 | EF3 | 62 km | 1.9 mi | 1 |
| Apr 16, 1961 | EF3 | 57 km | 0.1 mi | 0 |
| Apr 5, 1952 | EF3 | 66 km | 17.5 mi | 0 |
| Nov 4, 1950 | EF3 | 80 km | 15.9 mi | 0 |
| May 28, 2019 | EF2 | 98 km | 3.1 mi | 0 |
| Apr 19, 2019 | EF2 | 52 km | 4.9 mi | 0 |
| Apr 19, 2019 | EF2 | 89 km | 2.9 mi | 0 |
| Feb 24, 2016 | EF2 | 95 km | 4.9 mi | 0 |
| May 23, 2011 | EF2 | 32 km | 4.7 mi | 0 |
| Apr 28, 2011 | EF2 | 33 km | 2.6 mi | 0 |
| Apr 28, 2011 | EF2 | 40 km | 1.1 mi | 0 |
| Sep 18, 2004 | EF2 | 95 km | 2.0 mi | 0 |
| Sep 24, 2001 | EF2 | 74 km | 5.0 mi | 0 |
Source: NOAA Storm Prediction Center (EF0+, 1950-2024, US only).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 33°F (0°C) | 2.6 in | Coldest |
| February | 35°F (2°C) | 2.4 in | Driest |
| March | 43°F (6°C) | 3.4 in | |
| April | 54°F (12°C) | 3.7 in | |
| May | 64°F (18°C) | 3.5 in | |
| June | 73°F (23°C) | 3.7 in | |
| July | 78°F (25°C) | 4.3 in | Warmest, Wettest |
| August | 75°F (24°C) | 3.7 in | |
| September | 69°F (20°C) | 4.1 in | |
| October | 57°F (14°C) | 3.7 in | |
| November | 46°F (8°C) | 2.8 in | |
| December | 37°F (3°C) | 3.2 in |
Duncannon has a seasonal temperature swing of 45°F / from 33°F in January to 78°F in July. Total annual precipitation is 41.0 inches, with July being the wettest month (4.3") and February the driest (2.4").