All Countries
Chelsea, MA
Full City Profile · Massachusetts · Suffolk County County
2.5
/5.0
C+
Fair
39,460
Population
17,775/sq mi density
$72,220
Median Income
$31,544 per capita
$476,500
Home Value
$515,982 Zillow
$1,859
Median Rent
32.9% income on rent
52°F
Avg Temperature
246 sunny days/yr
667
Violent Crime/100K
1,467 property/100K
C+
Overall
2.5 / 5.0
Fair overall score based on economy, affordability, safety and education
B
Economy
3.3 / 5.0
$72,220 median income, 5.9% unemployment
C+
Affordability
2.9 / 5.0
$476,500 home value, $1,859/mo rent
F
Safety
1.0 / 5.0
667 violent crimes/100K (75% above avg)
C+
Education
2.8 / 5.0
22.0% bachelor's degree or higher
Chelsea experiences four distinct seasons with an average annual temperature of 52°F (11°C). Winters average 30°F in January while summers reach 74°F in July. The area gets 246 sunny days per year. Annual precipitation totals 43.6 inches. The area receives 49.2 inches of snow annually. Air quality is rated Good with a median AQI of 37.
Temperature
30°F Jan (-1°C)
74°F Jul (23°C)
| Annual Average | 51.9°F |
| 4% below US avg | |
| January Average | 30°F (-1°C) |
| July Average | 74°F (23°C) |
| Sunny Days | 246 days/yr |
Geography
| Elevation | 20 ft (6 m) |
| Area | 2.5 sq mi (6.4 km²) |
| Population Density | 17,775/sq mi |
| Coordinates | 42.3968°N, 71.0313°W |
| Timezone | America/New_York |
| County | Suffolk County County |
| Nearest Airport | General Edward Lawrence Logan International (BOS) 3 miles away |
Precipitation & Snow
Air Quality
| AQI Median | 37.0 |
| Rating | Good |
Air Pollutants (EPA 2023)
| Ozone (O₃) | 0.0356 ppm |
| NO₂ (Nitrogen Dioxide) | 15.7 ppb |
| SO₂ (Sulfur Dioxide) | 0.25 ppb |
| CO (Carbon Monoxide) | 0.29 ppm |
| PM2.5 (Fine Particles) | 7.3 μg/m³ |
Natural Hazard Risk
| Overall Risk | Relatively Moderate |
| Risk Score | 93.5 / 100 |
| Social Vulnerability | 70.6 / 100 |
| Community Resilience | 95.5 / 100 |
Hazard Breakdown
| Tornado | Relatively Moderate |
| Hurricane | Relatively High |
| Earthquake | Relatively Moderate |
| Wildfire | Very Low |
| Flood | Relatively High |
| Hail | Relatively Moderate |
| Strong Wind | Relatively Moderate |
| Heat Wave | Relatively High |
| Winter Weather | Relatively Low |
| Lightning | Very High |
| Ice Storm | Relatively Moderate |
| Drought | No Rating |
| Cold Wave | Relatively High |
| Landslide | Very Low |
| Coastal Flood | Relatively High |
Source: FEMA National Risk Index v1.20 (Dec 2025)
Monthly Weather
| Month | Avg Temperature | Precipitation | Summary |
|---|---|---|---|
| January | 30°F (-1°C) | 4.0 in | |
| February | 29°F (-2°C) | 3.4 in | Coldest |
| March | 37°F (3°C) | 4.0 in | |
| April | 47°F (8°C) | 3.7 in | |
| May | 58°F (14°C) | 3.4 in | |
| June | 67°F (20°C) | 3.4 in | |
| July | 74°F (23°C) | 3.3 in | Warmest, Driest |
| August | 72°F (22°C) | 3.5 in | |
| September | 64°F (18°C) | 3.6 in | |
| October | 53°F (11°C) | 3.9 in | |
| November | 43°F (6°C) | 4.1 in | Wettest |
| December | 32°F (0°C) | 3.9 in |
Chelsea has a seasonal temperature swing of 45°F / from 29°F in February to 74°F in July. Total annual precipitation is 44.4 inches, with November being the wettest month (4.1") and July the driest (3.3").