This map shows modeled outdoor noise across Ilwaco 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 131 Ilwaco residents, or 15.7%, live above that level. By land area, 13.2% of Ilwaco is above 55 dBA.
See how noise in Ilwaco compares to similar-sized cities.
Noise by Part of Ilwaco
Average noise levels for Ilwaco residents, grouped by direction from the center of Ilwaco. Central Ilwaco carries the highest population-weighted average; Northern Ilwaco carries the lowest. Just 0% of residents in Northern Ilwaco live in blocks above the EPA's 55 dBA threshold, a fifth of the share in Central Ilwaco.
Central Ilwaco
14% of people above 55 dBA
Eastern Ilwaco
18% of people above 55 dBA
Northern Ilwaco
0% of people above 55 dBA
Southern Ilwaco
22% of people above 55 dBA
Western Ilwaco
14% of people above 55 dBA
Central Ilwaco sounds about 168% louder than Northern Ilwaco to the human ear, a 14.2 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 US-101 do you need to be?
US-101 produces an estimated 56 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 30% of Ilwaco sits under tree canopy (about average for cities) and roughly 20% 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.