Sully, IA Noise Levels
Sully, IA: what the federal noise map shows
At Sully, IA, road, rail and aircraft noise all fall below the 45 dB(A) floor BTS's national map can distinguish from silence. That's the reading at Sully's Census-defined center point, not any one street, BTS's map is a live raster, not a per-address service.
Where Sully ranks
Sully is one of 8,515 places in this dataset with no measurable transportation noise at all, too quiet to rank on loudness. By population, it ranks 10,768 of the 12,137 places in this dataset, home to about 891 people.
Your street may differ from Sully's reading
For a single house or lot in Sully rather than the town-wide figure above, BTS's own map is the same free source, queried directly.
More on how this number was built
For exactly which federal dataset feeds Sully's figure, see the methodology guide. The guide to reading a quiet result explains what "no measurable noise" actually means at Sully.