This map shows modeled outdoor noise across Mountain View 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 5,283 Mountain View residents, or 37.4%, live above that level. By land area, 42.2% of Mountain View is above 55 dBA.
See how noise in Mountain View compares to similar-sized neighborhoods.
Noise by Part of Mountain View
Average noise levels for Mountain View residents, grouped by direction from the center of Mountain View. The highest population-weighted average is in northeastern Mountain View; the lowest is in western Mountain View, where just 33% of residents live in blocks above the EPA's 55 dBA threshold, roughly the same as the share in the loudest section.
Northeastern Mountain View
34% of people above 55 dBA
Northern Mountain View
31% of people above 55 dBA
Eastern Mountain View
41% of people above 55 dBA
Southeastern Mountain View
28% of people above 55 dBA
Western Mountain View
33% of people above 55 dBA
To the human ear, noise in northeastern Mountain View sounds about 55% louder than in western Mountain View, a 6.3 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 do you need to be?
produces an estimated 68 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.
Calculated from the model's calibrated attenuation formula. About 15% of Mountain View sits under tree canopy (about average for neighborhoods) and roughly 50% 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.