Alameda County, CA Noise Ordinances: Quiet Hours (2026)
Quiet hours in Alameda County, CA, also called the noise ordinance, nighttime noise rules, or residential quiet time, define the hours during which excessive noise is prohibited.
Key Facts
- Daytime hours
- 7 a.m. to 10 p.m.
- Nighttime hours
- 10 p.m. to 7 a.m.
- Lowest residential limit
- 45 dB(A) at night
- Tonal/music noise
- Extra 5 dB(A) reduction
- Applies in
- Unincorporated area only
Summary
Unincorporated Alameda County sets stricter nighttime decibel limits, 10 p.m. to 7 a.m., than its daytime standard for homes, schools, and commercial property: covering Castro Valley and other unincorporated communities only.
It is unlawful for any person...to create any noise...which causes the exterior noise level when measured at any single- or multiple-family residential, school, hospital, church, public library or commercial properties...to exceed the noise level standards as set forth in Table 6.60.040A or Table 6.60.040B following:...Daytime 7 a.m. to 10 p.m. Nighttime 10 p.m. to 7 a.m.
Full Breakdown
Alameda County Code § 6.60.040 bars exceeding the exterior noise-level standards in Tables 6.60.040A and 6.60.040B, which set lower decibel ceilings for the nighttime period, 10 p.m. to 7 a.m., than for daytime, 7 a.m. to 10 p.m., the lowest residential category allows 50 dB(A) by day but only 45 dB(A) at night, and speech, music, or other tonal noise gets an added 5 dB(A) reduction. This applies only in the unincorporated county, Castro Valley, San Lorenzo, and similar communities, never inside Oakland, Berkeley, or the county's other incorporated cities. The environmental health director enforces this section.
Violations & Fines
Exceeding the standard is an infraction: $100 for a first violation, $200 for a second within a year, $500 for each one after that, under § 6.60.090, plus possible nuisance abatement.
Frequently Asked Questions
Are the nighttime limits the same as daytime?
Does this apply in Oakland or Berkeley?
Sources & Official References
Other rules in Alameda County
How Alameda County compares: Cities with the Strictest Noise Ordinances·California rules heatmap·Compare Alameda County to another location·View the California noise ordinances overview
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