Casper, WY Noise Ordinances: Decibel Limits (2026)

Section 8.20.040 of the Casper Municipal Code sets the numeric ceiling behind the city's noise rules. It is unlawful to project sound, other than noise from cars, trucks or motorcycles, across a property line within a use district above the limits in Table 8.20.040, and a violation requires the sound to exceed the limit for more than ninety percent of a measurement period of at least ten minutes. The table sets daytime limits, running seven a.m. to nine p.m., of 55 dB(A) in residential districts, 60 dB(A) in business districts, 70 dB(A) in commercial districts and 80 dB(A) in industrial districts, and nighttime limits, nine p.m. to seven a.m., of 50, 55, 65 and 75 dB(A) for the same four district types.

Where sound crosses from one district into an adjoining district with a different limit, Section 8.20.040(B) applies the lower limit of the district the sound enters, not the district it came from. Measurements must be taken with a sound-level meter meeting American National Standards Institute Type II or better standards, using the meter's slow response setting, at or beyond the property line and about five feet above ground, per Section 8.20.040(C). For an elevated or directional source, Section 8.20.040(D) requires compliance to be maintained at any elevation along the boundary, not just at ground level.

These are the same limits Section 8.20.020 references when it treats a sound-equipment reading of 15 dB(A) over the table as automatic proof of violation. Exceeding the table is a misdemeanor under Chapter 1.28 per Section 8.20.070, with each day a separate offense, and the noise can be abated as a public nuisance under Section 8.20.080.