San Luis Obispo County, CA Noise Ordinances: Quiet Hours (2026)

San Luis Obispo County keeps two noise sections. Section 23.06.044 sits in Title 23, the Coastal Zone Land Use Ordinance, and governs the Coastal Zone. Section 22.10.120 sits in Title 22, the Land Use Ordinance, and governs the inland area. Their exterior tables carry the same numbers. Daytime is 7:00 a.m. to 10:00 p.m. and nighttime is 10:00 p.m. to 7:00 a.m. The hourly equivalent sound level (Leq) limit is 50 dB by day and 45 dB at night, and the maximum level is 70 dB by day and 65 dB at night.

The nighttime column carries a note in both sections: it applies only to uses that operate or are occupied during nighttime hours. The coastal table prints it as Note 1 and the inland table prints it as note (1), in the same words. Both sections also apply only when the land use affected by the noise is a listed noise-sensitive use: residential uses (other than residential accessory uses and temporary dwellings), hospitals and similar health care establishments, hotels and motels, bed and breakfast facilities, schools from pre-school through college and specialized training, churches, libraries and museums, public assembly and entertainment, offices, and outdoor sports and recreation. When the receiving use is outdoor sports and recreation, each exterior limit rises by 10 dB.

Three adjustments follow each table in both sections. If the measured ambient level exceeds the applicable standard, the standard becomes the ambient level plus one dB. Each exterior standard drops by five dB for simple tone noises, noises consisting primarily of speech or music, and recurring impulsive noises, so music at night faces 40 dB Leq and 60 dB maximum. If the source is continuous and cannot reasonably be stopped long enough to measure the ambient level, the reading taken while it runs is compared directly to the exterior standards.

The equipment limits for air conditioning, refrigeration and garbage trucks differ only in how their dates are written. The inland section fixes calendar dates: air conditioning and refrigeration equipment installed before June 4, 1992 is capped at 55 dB, and equipment installed or in use after June 4, 1993 at 50 dB. Waste collection equipment follows the same pattern: 85 dB for equipment in use, purchased or leased before December 4, 1992, and 75 dB for new equipment purchased or leased after June 4, 1995. The coastal section counts from the chapter's effective date.