All Countries
South Plainfield, NJ
Full City Profile · New Jersey · Union County County
3.7
/5.0
B+
Good
24,231
Population
2,919/sq mi density
$126,063
Median Income
$49,533 per capita
$443,900
Home Value
$570,339 Zillow
$1,928
Median Rent
27.9% income on rent
55°F
Avg Temperature
275 sunny days/yr
124
Violent Crime/100K
1,634 property/100K
B+
Overall
3.7 / 5.0
Good overall score based on economy, affordability, safety and education
A+
Economy
4.6 / 5.0
$126,063 median income, 5.0% unemployment
A+
Affordability
4.7 / 5.0
$443,900 home value, $1,928/mo rent
F
Safety
1.0 / 5.0
124 violent crimes/100K
A
Education
4.4 / 5.0
42.0% bachelor's degree or higher
South Plainfield experiences four distinct seasons with an average annual temperature of 55°F (13°C). Winters average 32°F in January while summers reach 77°F in July. The area gets 275 sunny days per year. Annual precipitation totals 48.7 inches. The area receives 21.4 inches of snow annually. Air quality is rated Good with a median AQI of 39.
Temperature
32°F Jan (0°C)
77°F Jul (25°C)
| Annual Average | 54.9°F |
| 2% above US avg | |
| January Average | 32°F (0°C) |
| July Average | 77°F (25°C) |
| Sunny Days | 275 days/yr |
Geography
| Elevation | 81 ft (25 m) |
| Area | 8.3 sq mi (21.6 km²) |
| Population Density | 2,919/sq mi |
| Coordinates | 40.5744°N, 74.4148°W |
| Timezone | America/New_York |
| County | Union County County |
| Nearest Airport | Central Jersey Regional (JVI) 10 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 39.0 |
| Rating | Good |
Air Pollutants (EPA 2023)
| NO₂ (Nitrogen Dioxide) | 26.6 ppb |
| SO₂ (Sulfur Dioxide) | 0.74 ppb |
| CO (Carbon Monoxide) | 0.42 ppm |
| PM2.5 (Fine Particles) | 9.8 μg/m³ |
Natural Hazard Risk
| Overall Risk | Relatively High |
| Risk Score | 95.5 / 100 |
| Social Vulnerability | 55.8 / 100 |
| Community Resilience | 30.3 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Relatively Moderate |
| Earthquake | Relatively Moderate |
| Wildfire | Very Low |
| Flood | Relatively High |
| Hail | Very Low |
| Strong Wind | Very High |
| Heat Wave | Relatively Moderate |
| Winter Weather | Very High |
| Lightning | Very High |
| Ice Storm | Very High |
| Drought | Very Low |
| Cold Wave | Relatively Moderate |
| Landslide | Very Low |
| Coastal Flood | Relatively Moderate |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Tsunami History
3 tsunamis recorded within 500 km. Highest wave on record: 0.3 m (1 ft).
| Year | Location | Cause | Max Wave | Deaths | Distance |
| 1964 | LONG ISLAND, NY | Meteorological | 0.3 m | — | 114 km |
| 1895 | HIGH BRIDGE, NJ | Earthquake | — | — | 41 km |
| 1840 | PHILADELPHIA, PENNSYLVANIA | Earthquake | — | — | 109 km |
Source: NOAA/NCEI Historical Tsunami Database. Sorted by wave height.
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 32°F (0°C) | 3.9 in | Coldest |
| February | 32°F (0°C) | 3.0 in | Driest |
| March | 41°F (5°C) | 4.1 in | |
| April | 51°F (10°C) | 4.1 in | |
| May | 61°F (16°C) | 4.6 in | |
| June | 70°F (21°C) | 4.0 in | |
| July | 77°F (25°C) | 5.1 in | Warmest, Wettest |
| August | 73°F (23°C) | 4.4 in | |
| September | 66°F (19°C) | 4.4 in | |
| October | 55°F (13°C) | 3.7 in | |
| November | 45°F (7°C) | 4.1 in | |
| December | 35°F (2°C) | 3.8 in |
South Plainfield has a seasonal temperature swing of 45°F / from 32°F in January to 77°F in July. Total annual precipitation is 49.4 inches, with July being the wettest month (5.1") and February the driest (3.0").