Noise Levels in Assumption Parish, San Leandro, CA | Find Quiet Neighborhoods With Our Sound Map
55 dBA
Average noise across Assumption Parish
Quiet office to normal conversation
1,905
Residents above the EPA 55 dBA threshold
49% of Assumption Parish residents
73 dBA
Loudest residential point
City bus interior
This map shows modeled outdoor noise across Assumption Parish 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.
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 1,905 Assumption Parish residents, or 48.6%, live above that level. By land area, 57.2% of Assumption Parish is above 55 dBA.
42.8% below 55 dBA
57.2% above 55 dBA
See how noise in Assumption Parish compares to similar-sized neighborhoods.
Noise by Part of Assumption Parish
Average noise levels for Assumption Parish residents, grouped by direction from the center of Assumption Parish. The highest population-weighted average is in southeastern Assumption Parish; the lowest is in northern Assumption Parish, where just 62% of residents live in blocks above the EPA's 55 dBA threshold, roughly the same as the share in the loudest section.
Southeastern Assumption Parish
63.7 dBA · Loud
Busy restaurant
Central Assumption Parish
58.7 dBA · Loud
Normal conversation an arm’s length away
Northern Assumption Parish
57.0 dBA · Moderate-loud
Normal conversation an arm’s length away
To the human ear, noise in southeastern Assumption Parish sounds about 59% louder than in northern Assumption Parish, a 6.7 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 Macarthur Fwy do you need to be?
Macarthur Fwy 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
63 dBA
Busy restaurant
330 ft
55 dBA
Quiet office to normal conversation
660 ft
46 dBA
Quiet office
¼ mile
38 dBA
Soft rainfall
½ mile
35 dBA
Soft rainfall
Calculated from the model's calibrated attenuation formula. About 5% of Assumption Parish sits under tree canopy (lighter than most neighborhoods) and roughly 57% 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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Airport Noise
San Francisco Bay Oakland International (OAK) sits west of Assumption Parish. The U.S. Department of Transportation models aviation noise around this airport from federal traffic data, 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 65 dBA on the map's Overall layer. Blocks on the opposite side of Assumption Parish, particularly to the east, show no measurable aviation contribution. Use the Aviation toggle on the map above to isolate the airport's footprint.
How Noise Is Distributed Across Assumption Parish
The bar chart below shows the share of Assumption Parish residents in each noise band. About 48% of residents live below the EPA's 55 dBA threshold, and roughly 10% live in blocks above 60 dBA. Long-term exposure in that range is linked to elevated stress hormones and cardiovascular risk.
How Assumption Parish Compares
Assumption Parish sits at the louder end of the spectrum. Below: how Assumption Parish's average outdoor noise and share of residents above the EPA threshold compare with Chabot Park, Elmhurst Park, Estudillo Estates-Glen, and Cox.
Average noise level (dBA)
Assumption Parish's 55.3 dBA pop-weighted average is at the louder end of the spectrum. California as a whole averages 54.0 dBA and the U.S. averages 52.0 dBA. Both are lower than Assumption Parish because most of either area is rural land away from major roads.
Share of residents above 55 dBA
About 48.6% of Assumption Parish residents live in blocks where outdoor levels exceed the EPA's 55 dBA threshold. That's in the middle of its peer group. Measured by land area instead, 57.2% of Assumption Parish's footprint sits above 55 dBA, against a California average of 36.0% and a national average of 28.1%.
What This Means if You're Moving to Assumption Parish
- 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 Macarthur Fwy 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 5% of Assumption Parish is under tree cover (lighter than most neighborhoods), 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. San Francisco Bay Oakland International's approach paths concentrate aviation noise to the west. Neighborhoods to the east of downtown show no measurable contribution from the airport.
