This map shows modeled outdoor noise across Porterville 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 19,201 Porterville residents, or 27.6%, live above that level. By land area, 26.2% of Porterville is above 55 dBA.
See how noise in Porterville compares to similar-sized cities.
Noise by Part of Porterville
Average noise levels for Porterville residents, grouped by direction from the center of Porterville. Central Porterville carries the highest population-weighted average; Southern Porterville carries the lowest. Just 13% of residents in Southern Porterville live in blocks above the EPA's 55 dBA threshold, a third of the share in Central Porterville.
Central Porterville
44% of people above 55 dBA
Eastern Porterville
26% of people above 55 dBA
Northern Porterville
35% of people above 55 dBA
Southern Porterville
13% of people above 55 dBA
Western Porterville
30% of people above 55 dBA
Central Porterville sounds about 44% louder than Southern Porterville to the human ear, a 5.3 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 State Rte 65 do you need to be?
State Rte 65 produces an estimated 67 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 1% of Porterville sits under tree canopy (much lighter than most cities) and roughly 34% 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.