This map shows modeled outdoor noise across Morro Bay 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 3,754 Morro Bay residents, or 42.2%, live above that level. By land area, 41.2% of Morro Bay is above 55 dBA.
See how noise in Morro Bay compares to similar-sized cities.
Noise by Part of Morro Bay
Average noise levels for Morro Bay residents, grouped by direction from the center of Morro Bay. Southern Morro Bay carries the highest population-weighted average; Eastern Morro Bay carries the lowest. Just 5% of residents in Eastern Morro Bay live in blocks above the EPA's 55 dBA threshold, a fifth of the share in Southern Morro Bay.
Central Morro Bay
15% of people above 55 dBA
Eastern Morro Bay
5% of people above 55 dBA
Northern Morro Bay
39% of people above 55 dBA
Southern Morro Bay
50% of people above 55 dBA
Western Morro Bay
38% of people above 55 dBA
Southern Morro Bay sounds about 108% louder than Eastern Morro Bay to the human ear, a 10.6 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 Cabrillo Hwy do you need to be?
Cabrillo Hwy 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 2% of Morro Bay sits under tree canopy (much lighter than most cities) 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.