Mono County, CA Noise Ordinances: Decibel Limits (2026)

Section 10.16.060 of the Mono County Code sets the maximum allowable exterior noise levels by land use, used when the background sound level cannot be determined. Table 10.16.060(A) caps low-density and multi-family residential, transient lodging, public uses (schools, libraries, hospitals, community and senior centers), and passive recreation, cultural and natural-habitat areas at 55 dBA daytime (7:00 a.m.-9:59 p.m.) and 50 dBA nighttime (10:00 p.m.-6:59 a.m.). Community parks and athletic fields are allowed 60 dBA at all times; commercial uses, offices and retail 65 dBA at all times; and light-industrial and industrial uses, utilities, mining, ranching and agriculture 65 dBA at all times. In addition to these absolute caps, Section 10.16.060(B) defines a noise disturbance as a sound exceeding the background level by at least 10 dBA in the daytime or 5 dBA at night, measured at the receiving property line. Pure tones reduce the limits by 5 dBA, and nonrepetitive impulsive sounds must not exceed 90 dBA (120 dBA peak) at a residential property line. These standards apply across the unincorporated communities of the Eastern Sierra and not within the Town of Mammoth Lakes.