10 county-level rules, plus city-specific rules for 4 cities in San Mateo County, California.
Verified from official government sources
In unincorporated San Mateo County, Noise Control Chapter 4.88 sets nighttime hours of 10:00 p.m. to 7:00 a.m. with stricter exterior dBA limits than the 7:00 a.m. to 10:00 p.m. daytime period, measured at residences, schools, hospitals, churches and libraries.
Under County Code 4.88.360, construction, demolition, repair, remodeling and grading in unincorporated San Mateo County is exempt from noise limits only between 7:00 a.m. and 6:00 p.m. on weekdays and 9:00 a.m. and 5:00 p.m. on Saturdays. No construction is allowed on Sundays, Thanksgiving or Christmas.
There is no separate barking-dog decibel rule for unincorporated San Mateo County; persistent barking is addressed under the County's General Noise Regulation (4.88.350), which prohibits unreasonably loud, unnecessary or unusual noise that disturbs the peace, with animal complaints handled through the County and its contracted animal-control services.
Unincorporated San Mateo County has no dedicated gas-powered leaf blower ban or specific leaf-blower ordinance; the recent leaf-blower bans and electric-blower rebate programs are city-level (e.g., City of San Mateo, Atherton, Redwood City). In unincorporated areas, blowers are governed by the general Chapter 4.88 noise standards.
Cal. AB 1346 (2021) - Small Off-Road Engines (Gas Leaf Blower Phase-Out)
Existing law imposes various limitations on the emissions of air contaminants for the control of air pollution from vehicular and nonvehicular sources. Existing law assigns the responsibility for controlling vehicular sources of air pollution to the State Air Resources Board. This bill would require the state board, by July 1, 2022, consistent with federal law, to adopt cost-effective and techn...
Amplified music in unincorporated San Mateo County is regulated by County Code Chapter 4.88: it must stay within the exterior dBA limits of Section 4.88.330 and must not be unreasonably loud under the General Noise Regulation (4.88.350). There is no separate county amplified-sound permit chapter in the noise code itself.
Aircraft noise is regulated by the FAA under federal law, not by the County's local noise ordinance. The County of San Mateo operates San Carlos and Half Moon Bay airports and runs a voluntary Airports Noise Abatement Program with voluntary flight procedures, a 'Fly Friendly' education effort and a noise-complaint hotline at (844) 266-6266.
Industrial and commercial noise in unincorporated San Mateo County is controlled through the exterior noise standards of County Code 4.88.330 (measured at nearby residences, schools, hospitals, churches and libraries) and the General Noise Regulation 4.88.350, with construction-noise exemptions limited to set hours under 4.88.360.
County Code 4.88.330 sets exterior noise limits at residences, schools, hospitals, churches and libraries on a sliding scale by how long the noise lasts in an hour. Daytime (7 a.m.-10 p.m.) limits run from 55 dBA (30 min/hr) up to 75 dBA (instantaneous max); nighttime (10 p.m.-7 a.m.) limits are 5 dBA lower, from 50 to 70 dBA.
Outdoor music in unincorporated San Mateo County must comply with the exterior decibel limits in County Code 4.88.330 and must not be unreasonably loud under 4.88.350. The County noise code has no special outdoor-music exemption, so evening and late-night events face the stricter 10 p.m.-7 a.m. nighttime limits.
Noise from motor vehicles operated on public roads in unincorporated San Mateo County is primarily controlled by the California Vehicle Code, which requires an adequate muffler and prohibits modified exhaust that amplifies noise. The County's Chapter 4.88 noise limits generally address stationary, on-property noise rather than vehicles in transit on public rights-of-way.
4 cities in San Mateo County have their own noise ordinances rules. Each link goes to that city's dedicated page with code citations.
7 verified rules • Aircraft Noise, Amplified Music & Events
10 verified rules • Aircraft Noise, Amplified Music & Events
3 verified rules • Barking Dogs, Construction Hours
3 verified rules • Barking Dogs, Construction Hours
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