This map shows modeled outdoor noise across 92404 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 19,899 92404 residents, or 35.5%, live above that level. By land area, 39.1% of 92404 is above 55 dBA.
See how noise in 92404 compares to similar-sized zip codes.
Noise by Part of 92404
Average noise levels for 92404 residents, grouped by direction from the center of 92404. Central 92404 carries the highest population-weighted average; Southern 92404 carries the lowest. Just 23% of residents in Southern 92404 live in blocks above the EPA's 55 dBA threshold, about half the share in Central 92404.
Central 92404
65% of people above 55 dBA
Eastern 92404
40% of people above 55 dBA
Northern 92404
33% of people above 55 dBA
Southern 92404
23% of people above 55 dBA
Western 92404
41% of people above 55 dBA
Central 92404 sounds about 91% louder than Southern 92404 to the human ear, a 9.3 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 Foothill Fwy do you need to be?
Foothill 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.
Calculated from the model's calibrated attenuation formula. About 4% of 92404 sits under tree canopy (much lighter than most zip codes) and roughly 47% 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.