Middleton, WI Noise Ordinances: Decibel Limits (2026)

31b. 4-1983 at the lot line of the property, where that lot abuts a residential, mixed-use, or institutional zoning district. 31a sets the maximum permitted increase over ambient noise level by district: SR-L, SR-M, SR-H, MH-D, TR-D, TR-F, MR-L, MR-M, MR-H, AGR, PR, and CON districts are capped at plus 3 dBA; INST, MU-N, MU-A, MU-U, and MU-D districts at plus 5 dBA; and I-L, R-P, I-M, I-H, IOS, IOC, and EXD industrial-type districts at plus 8 dBA. 31b layers on adjustment factors: daytime-only operation or a source running less than 20 percent of any hour adds 5 dBA of allowance, under 5 percent of an hour adds 10 dBA, and under 1 percent adds 15 dBA, while impulsive noise (hammering) or periodic noise (hum, speech) each subtract 5 dBA from the allowance.

Noise lawfully operating before the chapter's effective date is treated as legal nonconforming, but the noise producer bears the burden of proving that prior legality. The Section exempts noise from construction of the principal use and incidental traffic, parking, loading, maintenance, or agricultural operations.