Millbrae, CA Noise Levels
How loud is Millbrae, CA?
At 47.5 dB(A), Millbrae, CA 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. This describes Millbrae as a whole, not a specific block, the underlying BTS map resolves to about 38 meters per pixel, sampled at the town's own center point.
Where Millbrae'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 Millbrae
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 Millbrae compares nationally
Millbrae ranks 2,081 of 3,622 measured places nationally, 1 being the loudest this dataset covers. About 23,321 people live there, making it the 1,699th largest place in this dataset.
Checking one address in Millbrae
Nothing here substitutes for checking one address in Millbrae directly, and BTS's own map lets anyone do that at no cost.
Millbrae'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.