Noise Levels in St. Helena, CA | Find Quiet Neighborhoods With Our Sound Map
50 dBA
Average noise across St. Helena
Quiet office
933
Residents above the EPA 55 dBA threshold
17% of St. Helena residents
77 dBA
Loudest residential point
City bus interior
This map shows modeled outdoor noise across St. Helena 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 933 St. Helena residents, or 16.7%, live above that level. By land area, 18.3% of St. Helena is above 55 dBA.
81.7% below 55 dBA
18.3% above 55 dBA
See how noise in St. Helena compares to similar-sized cities.
Noise by Part of St. Helena
Average noise levels for St. Helena residents, grouped by direction from the center of St. Helena. Central St. Helena carries the highest population-weighted average; Northern St. Helena carries the lowest. Just 5% of residents in Northern St. Helena live in blocks above the EPA's 55 dBA threshold, a fifth of the share in Central St. Helena.
Central St. Helena
51.5 dBA · Moderate
Quiet office to normal conversation
Eastern St. Helena
46.6 dBA · Mostly quiet
Quiet office
Northern St. Helena
46.5 dBA · Mostly quiet
Quiet office
Southern St. Helena
50.9 dBA · Moderate
Quiet office
Western St. Helena
51.2 dBA · Moderate
Quiet office to normal conversation
Central St. Helena sounds about 41% louder than Northern St. Helena to the human ear, a 5.0 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 77 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.
At source
77 dBA
City bus interior
165 ft
63 dBA
Busy restaurant
330 ft
56 dBA
Quiet office to normal conversation
660 ft
48 dBA
Quiet office
¼ mile
40 dBA
Soft rainfall
½ mile
35 dBA
Soft rainfall
Calculated from the model's calibrated attenuation formula. About 10% of St. Helena sits under tree canopy (lighter than most cities) and roughly 25% 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.
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Rail Noise
Active freight rail runs through parts of St. Helena. For most blocks the rail-only contribution is small. Combined road-plus-rail noise rarely exceeds road noise on its own. The exceptions are the handful of blocks within roughly a quarter mile of the right-of-way during pass-through hours.
Use the Rail toggle on the map above to isolate rail's contribution from road and aviation.
How Noise Is Distributed Across St. Helena
The bar chart below shows the share of St. Helena residents in each noise band. About 84% of residents live below the EPA's 55 dBA threshold, and roughly 1% live in blocks above 60 dBA. Long-term exposure in that range is linked to elevated stress hormones and cardiovascular risk.
How St. Helena Compares
St. Helena sits the highest among the peer group. Below: how St. Helena's average outdoor noise and share of residents above the EPA threshold compare with Calistoga, Penngrove, Forestville, and Yountville.
Average noise level (dBA)
St. Helena's 49.6 dBA pop-weighted average is the highest among the peer group. California as a whole averages 54.0 dBA and the U.S. averages 52.0 dBA. Both are lower than St. Helena because most of either area is rural land away from major roads.
Share of residents above 55 dBA
About 16.7% of St. Helena residents live in blocks where outdoor levels exceed the EPA's 55 dBA threshold. That's more than any of its peer group. Measured by land area instead, 18.3% of St. Helena's footprint sits above 55 dBA, against a California average of 36.0% and a national average of 28.1%.
What This Means if You're Moving to St. Helena
- Distance from highways matters more than the neighborhood name. Two homes in the same zip code can differ by 20 dBA if one sits 100 meters from and the other 500 meters away. The model captures this at 100-meter resolution, so noise exposure changes block by block.
- Tree canopy can help reduce modeled noise exposure. Roughly 10% of St. Helena is under tree cover (lighter than most cities), and the dominant land cover is low-intensity developed land. Both are measured from federal USDA Forest Service and USGS satellite imagery at 30-meter resolution. Streets with 60% or higher canopy show 3 to 5 dBA lower noise than comparable streets with bare ground or pavement, which is why the per-place decay rate above already accounts for it.
