Weather & Climate in Marmora, NJ
Temperature, precipitation, air quality, natural hazards, and monthly weather data.
Marmora experiences four distinct seasons with an average annual temperature of 55°F (13°C). Winters average 34°F in January while summers reach 77°F in July. Annual precipitation totals 46.0 inches (wetter than the 38-inch national average). The area receives 17.4 inches of snow annually, a moderate snowfall amount. Air quality is rated Good with a median AQI of 35. 83% of days have good air quality. The city sits at an elevation of 15 feet.
Temperature
34°F Jan (1°C)
77°F Jul (25°C)
| Annual Average | 55.1°F |
| 2% above US avg | |
| January Average | 34°F (1°C) |
| July Average | 77°F (25°C) |
Geography
| Elevation | 15 ft (5 m) |
| Area | 2.0 sq mi (5.2 km²) |
| Population Density | 1,001/sq mi |
| Coordinates | 39.2587°N, 74.6574°W |
| Timezone | America/New_York |
| County | Atlantic County County |
| Nearest Airport | Atlantic City International (ACY) 14 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 35.0 |
| Rating | Good |
| Good Days % | 82.5% |
| Unhealthy Days | 0 |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 93.0 / 100 |
| Social Vulnerability | 46.5 / 100 |
| Community Resilience | 83.0 / 100 |
Hazard Breakdown
| Tornado | Relatively Low |
| Hurricane | Relatively High |
| Earthquake | Relatively Low |
| Wildfire | Relatively Moderate |
| Flood | Relatively Moderate |
| Hail | Relatively Low |
| Strong Wind | Very High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Very High |
| Lightning | Relatively High |
| Ice Storm | Relatively Moderate |
| Drought | Relatively Moderate |
| Cold Wave | Relatively Moderate |
| Landslide | Very Low |
| Coastal Flood | Very High |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Earthquake History
7 earthquakes (M2.5+) recorded within 150 km since 1990. Strongest on record: M3.2.
| Oct 23, 1990 | 3 km W of Hancocks Bridge, New Jersey | M3.2 | 78 km | 10 km |
| Jan 9, 1992 | 4 km WNW of Robertsville, New Jersey | M3.1 | 126 km | 8 km |
| Jul 1, 2009 | 3 km ESE of Pennsville, New Jersey | M2.8 | 83 km | 5 km |
| Jan 25, 2015 | 4 km ESE of Downingtown, Pennsylvania | M2.6 | 119 km | 2 km |
| Jul 5, 1996 | 2 km NW of Chester Heights, Pennsylvania | M2.6 | 102 km | 18 km |
| Feb 9, 2023 | 29 km E of Greenbackville, Virginia | M2.6 | 141 km | 11 km |
| Feb 26, 1993 | 2 km SW of Marlton, New Jersey | M2.5 | 73 km | 5 km |
Source: USGS Earthquake Catalog (M2.5+, 1990-2025). Sorted by magnitude.
Hurricane History
9 hurricanes (Category 1+) recorded within 500 km since 1980. Strongest on record: Category 3.
| Year | Name | Category | Max Wind | Closest |
| 2014 | Arthur | Category 1 | 92 mph | 210 km |
| 2012 | Sandy | Category 2 | 92 mph | 165 km |
| 2011 | Irene | Category 1 | 75 mph | 132 km |
| 2010 | Earl | Category 1 | 81 mph | 283 km |
| 1998 | Bonnie | Category 1 | 75 mph | 286 km |
| 1993 | Emily | Category 3 | 115 mph | 254 km |
| 1991 | Bob | Category 3 | 109 mph | 149 km |
| 1986 | Charley | Category 1 | 75 mph | 212 km |
| 1985 | Gloria | Category 2 | 98 mph | 97 km |
Source: NOAA IBTrACS (Category 1+, 1980-2026).
Tornado History
163 tornadoes (EF0+) recorded within 100 km since 1950. Strongest on record: EF3. Total: 3 fatalities, 143 injuries.
| Date | Rating | Distance | Path | Fatalities |
| Sep 1, 2021 | EF3 | 69 km | 12.4 mi | 0 |
| Jul 21, 1983 | EF3 | 56 km | 0.2 mi | 0 |
| Apr 28, 1961 | EF3 | 91 km | 0.3 mi | 0 |
| Jul 29, 2021 | EF2 | 68 km | 4.2 mi | 0 |
| Aug 4, 2020 | EF2 | 75 km | 35.8 mi | 0 |
| Aug 4, 2020 | EF2 | 95 km | 20.8 mi | 0 |
| Sep 28, 2004 | EF2 | 94 km | 5.0 mi | 0 |
| Aug 20, 1999 | EF2 | 48 km | 0.4 mi | 0 |
| Sep 27, 1993 | EF2 | 99 km | 10.0 mi | 0 |
| Aug 21, 1993 | EF2 | 44 km | 1.5 mi | 0 |
| Jul 31, 1992 | EF2 | 79 km | 4.0 mi | 0 |
| Oct 18, 1990 | EF2 | 98 km | 1.0 mi | 0 |
| May 10, 1990 | EF2 | 40 km | 0.5 mi | 0 |
| Jun 9, 1989 | EF2 | 88 km | 2.0 mi | 0 |
| Aug 17, 1988 | EF2 | 87 km | 1.5 mi | 0 |
| Jul 21, 1987 | EF2 | 12 km | 0.5 mi | 0 |
| Jul 18, 1984 | EF2 | 95 km | 1.5 mi | 0 |
| Jul 21, 1983 | EF2 | 92 km | 1.0 mi | 2 |
| Jun 29, 1982 | EF2 | 77 km | 1.5 mi | 0 |
| Sep 5, 1979 | EF2 | 91 km | 2.5 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 | - | - | 76 km |
Source: NOAA/NCEI Historical Tsunami Database.
Wildfire History
20 wildfires (100+ acres) recorded within 100 km. Largest: GREENWOOD STATE FOREST (21,271 acres, 1995).
| Year | Name | Acres Burned | Distance |
| 1995 | GREENWOOD STATE FOREST | 21,271 | 72 km |
| 2007 | WARREN GROVE | 15,315 | 56 km |
| 2022 | MULLICA RIVER FIRE | 13,082 | 48 km |
| 1999 | BASS RIVER | 12,129 | 48 km |
| 2019 | SPRING HILL FIRE | 8,182 | 62 km |
| 2023 | ALLEN ROAD | 6,213 | 46 km |
| 1992 | FORKED RIVER MOUTAIN APR | 5,093 | 74 km |
| 1992 | POWER PLANT | 4,928 | 74 km |
| 1992 | UNNAMED | 4,470 | 83 km |
| 2024 | TEA TIME HILL | 4,444 | 59 km |
| 2006 | UNNAMED | 3,780 | 51 km |
| 2017 | PENN SWAMP FIRE | 3,587 | 47 km |
| 2023 | JIMMYS WATER HOLE | 3,585 | 87 km |
| 1989 | SIMM PLACE | 3,262 | 61 km |
| 2002 | UNNAMED | 2,824 | 84 km |
| 2007 | ATSION | 2,705 | 52 km |
| 1992 | FOUR MILE COLONY | 2,647 | 68 km |
| 1996 | UNNAMED | 2,625 | 47 km |
| 2010 | FORT DIX RANGE 1-14 | 2,615 | 85 km |
| 1990 | UNNAMED | 2,367 | 58 km |
Source: NIFC/IRWIN Wildfire Records (100+ acres).
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 34°F (1°C) | 3.4 in | Coldest |
| February | 36°F (2°C) | 3.2 in | Driest |
| March | 43°F (6°C) | 4.5 in | |
| April | 53°F (11°C) | 3.3 in | |
| May | 62°F (17°C) | 3.3 in | |
| June | 71°F (22°C) | 3.6 in | |
| July | 77°F (25°C) | 4.5 in | Warmest |
| August | 75°F (24°C) | 4.6 in | Wettest |
| September | 68°F (20°C) | 3.6 in | |
| October | 57°F (14°C) | 4.1 in | |
| November | 47°F (8°C) | 3.4 in | |
| December | 39°F (4°C) | 4.5 in |
Marmora has a seasonal temperature swing of 43°F / from 34°F in January to 77°F in July. Total annual precipitation is 46.0 inches, with August being the wettest month (4.6") and February the driest (3.2").