Santa Cruz, CA Noise Ordinances: Decibel Limits (2026)

Unincorporated Santa Cruz County applies numeric decibel standards in two places. First, SCCC 8.30.010 (Offensive Noise) sets enforcement thresholds: between 8:00 a.m. and 10:00 p.m., a noise above 75 decibels at the edge of the source property line is automatically offensive; between 10:00 p.m. and 8:00 a.m., that drops to 60 decibels. Measurements use a sound-level meter meeting ANSI Standard S1.4-1971 (or later) for Type 1 or Type 2 meters. Second, the County General Plan Noise Element (Table 9-3, Maximum Allowable Noise Exposure for Stationary Noise Sources) sets land-use planning limits measured at the receiving property line: daytime (7 a.m. to 10 p.m.) hourly Leq of 50 dB and maximum level of 70 dB (65 dB for impulsive noise); nighttime (10 p.m. to 7 a.m.) hourly Leq of 45 dB and maximum level of 65 dB (60 dB impulsive). These Table 9-3 limits adjust to ambient conditions: allowable levels rise to the ambient level where ambient exceeds them, and drop 5 dB where the ambient hourly Leq is at least 10 dB below the limit. The Chapter 8.30 thresholds are the enforcement trigger for nuisance complaints, while Table 9-3 is applied to new commercial/industrial development through the permitting process.