This map shows modeled outdoor noise across San Ysidro 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 17,006 San Ysidro residents, or 62.0%, live above that level. By land area, 70.8% of San Ysidro is above 55 dBA.
See how noise in San Ysidro compares to similar-sized cities.
Noise by Part of San Ysidro
Average noise levels for San Ysidro residents, grouped by direction from the center of San Ysidro. Western San Ysidro carries the highest population-weighted average; Southern San Ysidro carries the lowest. Just 46% of residents in Southern San Ysidro live in blocks above the EPA's 55 dBA threshold, about half the share in Western San Ysidro.
Central San Ysidro
53% of people above 55 dBA
Eastern San Ysidro
64% of people above 55 dBA
Northern San Ysidro
50% of people above 55 dBA
Southern San Ysidro
46% of people above 55 dBA
Western San Ysidro
92% of people above 55 dBA
Western San Ysidro sounds about 106% louder than Southern San Ysidro to the human ear, a 10.4 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.
Loudest Road Corridors
The model evaluates every road in San Ysidro using federal traffic counts, posted speeds, heavy-truck ratios, and pavement type. The source level shown is the modeled noise at the road centerline, where it is loudest. Noise drops with distance, faster in vegetated areas and slower over open pavement.
How far back from San Diego Fwy do you need to be?
San Diego Fwy produces an estimated 80 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 3% of San Ysidro sits under tree canopy (much lighter than most cities) and roughly 57% 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.
Rail Noise
Active freight rail runs through parts of San Ysidro. 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.
Airport Noise
San Diego International (SAN) sits northwest of San Ysidro. The U.S. Department of Transportation measures aviation noise around this airport directly, and the model uses those federal measurements rather than synthetic predictions.
Blocks under the approach and departure paths carry combined road-plus-aviation noise, with some exceeding 70 dBA on the map's Overall layer. Blocks on the opposite side of San Ysidro, particularly to the southeast, show no measurable aviation contribution. Use the Aviation toggle on the map above to isolate the airport's footprint.
How Noise Is Distributed Across San Ysidro
The bar chart below shows the share of San Ysidro residents in each noise band. About 26% of residents live below the EPA's 55 dBA threshold, and roughly 32% live in blocks above 60 dBA. Long-term exposure in that range is linked to elevated stress hormones and cardiovascular risk.
How San Ysidro Compares
San Ysidro sits the highest among the peer group. Below: how San Ysidro's average outdoor noise and share of residents above the EPA threshold compare with Spring Valley, Lemon Grove, Imperial Beach, and La Presa.
Average noise level (dBA)
San Ysidro's 60.6 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 San Ysidro because most of either area is rural land away from major roads.
Share of residents above 55 dBA
About 62.0% of San Ysidro 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, 70.8% of San Ysidro'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 San Ysidro
- 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 San Diego Fwy 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 3% of San Ysidro is under tree cover (much lighter than most cities), and the dominant land cover is medium-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.
- Airport noise is directional. San Diego International's approach paths concentrate aviation noise to the northwest. Neighborhoods to the southeast of downtown show no measurable contribution from the airport.
Sources & Methodology
The BestNeighborhood noise model is calibrated against nearly one million federal ground-truth measurements across four states. Road noise is computed from segment-level federal traffic data and propagated outward using physics-based acoustic decay, with attenuation rates that depend on the surrounding land cover.
Federal datasets used:
FHWA Highway Performance Monitoring System: road geometry, traffic counts, lane configuration
U.S. DoT Bureau of Transportation Statistics National Transportation Noise Map: aviation and rail noise, road calibration ground truth
USGS / MRLC National Land Cover Database: land cover and impervious surface coverage
USDA Forest Service Tree Canopy Cover: vegetation density for sound propagation
U.S. Census Bureau TIGER/Line: block-level geography and population
U.S. EPA Levels Document: 55 dBA outdoor reference level
All inputs are published federal datasets. Block-level noise is computed by combining road, rail, and aviation sound sources in the energy domain, the same physics used in professional environmental noise assessments. Read the full methodology.