San Bernardino County, CA Noise Ordinances: Decibel Limits (2026)

The County's quantitative noise standards are in the Development Code, Section 83.01.080(c), 'Noise Standards for Stationary Noise Sources.' Table 5 sets the limit by the affected (receiving) land use and time of day. Residential: 55 dB(A) Leq from 7:00 a.m.-10:00 p.m. and 45 dB(A) Leq from 10:00 p.m.-7:00 a.m. Professional Services: 55 dB(A) both periods. Other Commercial: 60 dB(A) both periods. Industrial: 70 dB(A) both periods. Measurements use the A-weighted scale (dB(A)) and the equivalent energy level (Leq). The standard may be exceeded on a duration-based sliding scale (Section 83.01.080(c)(2)): the base standard for a cumulative period of more than 30 minutes per hour; the standard plus 5 dB(A) for more than 15 minutes; plus 10 dB(A) for more than 5 minutes; plus 15 dB(A) for more than 1 minute; and plus 20 dB(A) for no period of time. The County also sets exterior mobile-source standards (Table 6: 60 dB(A) Ldn/CNEL exterior for residential) and interior standards for new structures (Table 7). These are land-use development standards; motor vehicles on roads are exempt and governed by state law instead.