Union City, CA Noise Ordinances: Decibel Limits (2026)
Key Facts
- Residential
- 10 dBA above ambient
- Commercial/industrial
- 12 dBA above ambient
- Public property
- 15 dBA at 25+ feet
- Ambient floor
- never below 40 dBA
Summary
Union City caps added noise at 10 dBA above ambient on residential land, 12 dBA on commercial and industrial property, and 15 dBA on public property, each measured outside the property line.
No person shall produce, suffer or allow to be produced by any machine, animal or device, or any combination of same, on residential property, a noise level more than 10 dBA above the local ambient at any point outside of the property plane.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4940544; v16 updated 2026-06-23).
Full Breakdown
Chapter 9.40's zone-based scheme sets three separate ceilings above the 'local ambient' noise level, which the ordinance defines as the lowest repeating sound level over a six-minute measurement with a precision meter (never treated as below 40 dBA). Residential property is capped at 10 dBA above ambient outside the property plane under § 9.40.041; commercial and industrial property gets a 12 dBA allowance under § 9.40.042; and public property gets 15 dBA measured at 25 feet or more under § 9.40.043. These are separate from, and independent of, the general 'noise disturbance' prohibition in § 9.40.040: a sound can violate one standard without violating the other.
Violations & Fines
Exceeding these limits is enforceable as a misdemeanor under the citywide penalty chapter, up to $1,000 and six months in jail, or as a lesser infraction, and each standard is independently violable.
Frequently Asked Questions
What's the noise limit for a house in Union City?
Are commercial properties allowed louder noise than homes?
Sources & Official References
Other rules in Union City
California rules heatmap·Compare Union City to another location·View the California noise ordinances overview
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Decibel Limits in Nearby Cities
How other cities in Alameda County handle decibel limits.