Noise Levels in Southgate Triangle, Missoula, MT | Find Quiet Neighborhoods With Our Sound Map
54 dBA
Average noise across Southgate Triangle
Quiet office to normal conversation
1,135
Residents above the EPA 55 dBA threshold
42% of Southgate Triangle residents
70 dBA
Loudest residential point
Highway traffic 50 ft away
This map shows modeled outdoor noise across Southgate Triangle 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 1,135 Southgate Triangle residents, or 42.5%, live above that level. By land area, 48.3% of Southgate Triangle is above 55 dBA.
51.7% below 55 dBA
48.3% above 55 dBA
See how noise in Southgate Triangle compares to similar-sized neighborhoods.
Noise by Part of Southgate Triangle
Average noise levels for Southgate Triangle residents, grouped by direction from the center of Southgate Triangle. The highest population-weighted average is in northeastern Southgate Triangle; the lowest is in southwestern Southgate Triangle, where just 24% of residents live in blocks above the EPA's 55 dBA threshold, about half the share in the loudest section.
Northeastern Southgate Triangle
59.7 dBA · Loud
Normal conversation an arm’s length away
Northern Southgate Triangle
58.4 dBA · Loud
Normal conversation an arm’s length away
Central Southgate Triangle
58.3 dBA · Loud
Normal conversation an arm’s length away
Southwestern Southgate Triangle
52.6 dBA · Moderate
Quiet office to normal conversation
To the human ear, noise in northeastern Southgate Triangle sounds about 64% louder than in southwestern Southgate Triangle, a 7.1 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 70 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
70 dBA
Highway traffic 50 ft away
165 ft
56 dBA
Quiet office to normal conversation
330 ft
47 dBA
Quiet office
660 ft
39 dBA
Soft rainfall
¼ mile
35 dBA
Soft rainfall
½ mile
35 dBA
Soft rainfall
Calculated from the model's calibrated attenuation formula. About 5% of Southgate Triangle sits under tree canopy (lighter than most neighborhoods) and roughly 51% 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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Airport Noise
Missoula Montana (MSO) sits northwest of Southgate Triangle. The U.S. Department of Transportation models aviation noise around this airport from federal traffic data, 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 55 dBA on the map's Overall layer. Blocks on the opposite side of Southgate Triangle, 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 Southgate Triangle
The bar chart below shows the share of Southgate Triangle residents in each noise band. About 72% 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 Southgate Triangle Compares
Southgate Triangle sits at the quieter end of the spectrum. Below: how Southgate Triangle's average outdoor noise and share of residents above the EPA threshold compare with South 39th Street, farviews-and-pattee-canyon-missoula-mt, riverfront-missoula-mt, and Northside.
Average noise level (dBA)
Southgate Triangle's 53.7 dBA pop-weighted average is at the quieter end of the spectrum. Montana as a whole averages 49.0 dBA and the U.S. averages 52.0 dBA. Both are lower than Southgate Triangle because most of either area is rural land away from major roads.
Share of residents above 55 dBA
About 42.5% of Southgate Triangle residents live in blocks where outdoor levels exceed the EPA's 55 dBA threshold. That's in the middle of its peer group. Measured by land area instead, 48.3% of Southgate Triangle's footprint sits above 55 dBA, against a Montana average of 16.9% and a national average of 28.1%.
What This Means if You're Moving to Southgate Triangle
- 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 5% of Southgate Triangle is under tree cover (lighter than most neighborhoods), 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.
- Airport noise is directional. Missoula Montana's approach paths concentrate aviation noise to the northwest. Neighborhoods to the southeast of downtown show no measurable contribution from the airport.
