South Portland, ME Noise Levels
How loud is South Portland, ME?
At 47.5 dB(A), South Portland, ME falls inside HUD's "Acceptable" noise zone, 65 dB(A) day-night average or below under 24 CFR 51.104, the federal government's own line for building housing with no extra sound attenuation required. The main source is aircraft, well ahead of the other two modes BTS tracks. Treat this as South Portland's one representative point, not a promise about every block in it, BTS's map wasn't built to resolve individual streets.
Where South Portland's noise comes from
BTS models these three sources separately before combining them, so a place can be quiet on two and loud on the third.
If you're weighing a move to South Portland
Aircraft noise is intermittent and lower-frequency, which is why FAA’s Part 150 program funds whole-envelope sound insulation for homes inside an airport’s own mapped noise contour rather than relying on window replacement alone.
How South Portland compares nationally
South Portland ranks 2,038 of 3,622 measured places nationally, 1 being the loudest this dataset covers. About 26,994 people live there, making it the 1,480th largest place in this dataset.
Checking one address in South Portland
Nothing here substitutes for checking one address in South Portland directly, and BTS's own map lets anyone do that at no cost.
South Portland's number isn't a one-off calculation, it comes from the same method covered in the methodology guide. The guide to what actually cuts each kind of noise explains why aircraft calls for a different fix than the other two sources.