Noise Levels in Somerville, MA | Find Quiet Neighborhoods With Our Sound Map
58 dBA
Average noise across Somerville
Normal conversation an arm’s length away
50,162
Residents above the EPA 55 dBA threshold
74% of Somerville residents
98 dBA
Loudest residential point
Power saw
This map shows modeled outdoor noise across Somerville at 100-meter resolution, combining road, aviation, and rail sources. Green areas measure below 45 dBA. Orange and red exceed the EPA's 55 dBA outdoor threshold linked to long-term health effects. Use the layer toggles to view each source on its own or all together.
Overall
Road
Rail
Aviation
Click the map to explore
35 dBa55 dBa (EPA limit)90+ dBa
3545557090
Quietest (dBA)Loudest
Colorblind friendlyoff
What the numbers sound like
30 dBAWhisper
40 dBASoft rainfall
45 dBAQuiet suburban street at night
50 dBAQuiet office
55 dBAEPA outdoor threshold: light traffic 100 ft away
60 dBANormal conversation an arm's length away
65 dBABusy restaurant
70 dBAHighway traffic 50 ft away
80 dBACity bus interior
Population Above the EPA Outdoor Threshold
The EPA's 55 dBA outdoor reference level is a common benchmark for residential noise exposure, especially for activity interference, annoyance, and long-term community noise concerns. About 50,162 Somerville residents, or 73.5%, live above that level. By land area, 75.6% of Somerville is above 55 dBA.
Average noise levels for Somerville residents, grouped by direction from the center of Somerville. Eastern Somerville carries the highest population-weighted average; Western Somerville carries the lowest. Just 68% of residents in Western Somerville live in blocks above the EPA's 55 dBA threshold, three-quarters of the share in Eastern Somerville.
Central Somerville
57.6 dBA · Moderate-loud
Normal conversation an arm’s length away
63% of people above 55 dBA
QuietLoud
Eastern Somerville
60.1 dBA · Loud
Normal conversation an arm’s length away
84% of people above 55 dBA
QuietLoud
Northern Somerville
57.0 dBA · Moderate-loud
Normal conversation an arm’s length away
60% of people above 55 dBA
QuietLoud
Southern Somerville
58.3 dBA · Loud
Normal conversation an arm’s length away
77% of people above 55 dBA
QuietLoud
Western Somerville
56.5 dBA · Moderate-loud
Normal conversation an arm’s length away
68% of people above 55 dBA
QuietLoud
Eastern Somerville sounds about 28% louder than Western Somerville to the human ear, a 3.6 dBA gap. Every 10 dBA roughly doubles perceived loudness. Within any of these directions, two homes a quarter mile apart can still differ by 10 or more dBA depending on how close they sit to a major highway.
How far back from I-93 do you need to be?
I-93 produces an estimated 78 dBA at its loudest centerline points. Noise drops logarithmically with distance, with the exact rate depending on what's between you and the road. Tree cover, walls, terrain, and pavement type all matter. At roughly a quarter mile back, traffic fades into the noise level of a soft rainfall.
At source
78 dBA
City bus interior
165 ft
64 dBA
Busy restaurant
330 ft
56 dBA
Quiet office to normal conversation
660 ft
48 dBA
Quiet office
¼ mile
40 dBA
Soft rainfall
½ mile
35 dBA
Soft rainfall
Calculated from the model's calibrated attenuation formula. About 14% of Somerville sits under tree canopy (lighter than most cities) and roughly 70% is impervious surface like pavement and rooftops. Both are folded into the per-place decay rate above. Heavier canopy pulls noise down faster with distance; impervious surfaces slow the drop.
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Rail Noise
Active freight rail runs through parts of Somerville. For most blocks the rail-only contribution is small. Combined road-plus-rail noise rarely exceeds road noise on its own. The exceptions are the handful of blocks within roughly a quarter mile of the right-of-way during pass-through hours.
Use the Rail toggle on the map above to isolate rail's contribution from road and aviation.
Airport Noise
General Edward Lawrence Logan International (BOS) sits east of Somerville. The U.S. Department of Transportation measures aviation noise around this airport directly, and the model uses those federal measurements rather than synthetic predictions.
Blocks under the approach and departure paths carry combined road-plus-aviation noise, with some exceeding 45 dBA on the map's Overall layer. Blocks on the opposite side of Somerville, particularly to the west, show no measurable aviation contribution. Use the Aviation toggle on the map above to isolate the airport's footprint.
How Noise Is Distributed Across Somerville
The bar chart below shows the share of Somerville residents in each noise band. About 19% of residents live below the EPA's 55 dBA threshold, and roughly 25% live in blocks above 60 dBA. Long-term exposure in that range is linked to elevated stress hormones and cardiovascular risk.
How Somerville Compares
Somerville sits at the quieter end of the spectrum. Below: how Somerville's average outdoor noise and share of residents above the EPA threshold compare with Cambridge, Malden, Medford, and Waltham.
Average noise level (dBA)
Somerville's 58.1 dBA pop-weighted average is at the quieter end of the spectrum. Massachusetts as a whole averages 54.3 dBA and the U.S. averages 52.0 dBA. Both are lower than Somerville because most of either area is rural land away from major roads.
Share of residents above 55 dBA
About 73.5% of Somerville residents live in blocks where outdoor levels exceed the EPA's 55 dBA threshold. That's more than any of its peer group. Measured by land area instead, 75.6% of Somerville's footprint sits above 55 dBA, against a Massachusetts average of 40.0% and a national average of 28.1%.
What This Means if You're Moving to Somerville
Distance from highways matters more than the neighborhood name. Two homes in the same zip code can differ by 20 dBA if one sits 100 meters from I-93 and the other 500 meters away. The model captures this at 100-meter resolution, so noise exposure changes block by block.
Tree canopy can help reduce modeled noise exposure. Roughly 14% of Somerville is under tree cover (lighter than most cities), and the dominant land cover is medium-intensity developed land. Both are measured from federal USDA Forest Service and USGS satellite imagery at 30-meter resolution. Streets with 60% or higher canopy show 3 to 5 dBA lower noise than comparable streets with bare ground or pavement, which is why the per-place decay rate above already accounts for it.
Airport noise is directional. General Edward Lawrence Logan International's approach paths concentrate aviation noise to the east. Neighborhoods to the west of downtown show no measurable contribution from the airport.
Sources & Methodology
The BestNeighborhood noise model is calibrated against nearly one million federal ground-truth measurements across four states. Road noise is computed from segment-level federal traffic data and propagated outward using physics-based acoustic decay, with attenuation rates that depend on the surrounding land cover.
All inputs are published federal datasets. Block-level noise is computed by combining road, rail, and aviation sound sources in the energy domain, the same physics used in professional environmental noise assessments. Read the full methodology.
