Union City, CA Noise Ordinances: Quiet Hours (2026)
Quiet hours in Union City, 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 exemption
- 8am-8pm weekdays/Saturday
- Sunday/holiday window
- 10am-6pm only
- After hours
- full Ch. 9.40 limits apply
- Exemption threshold
- under 70 dBA at 25 ft
Summary
Union City has no separate nighttime curfew ordinance: instead, a daytime exemption for noise under 70 dBA at 25 feet lapses at 8 p.m. (6 p.m. Sundays/holidays), leaving the stricter ambient-based limits in force overnight.
Any noise source which does not produce a noise level exceeding seventy dBA at a distance of twenty-five feet from the noise source under its most noisy condition of use shall be exempt from the provisions of Article 4 between the hours of eight a.m. and eight p.m. daily except Sundays and holidays, when the exemption herein shall apply between ten a.m. and six p.m.
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
Section 9.40.050 doesn't set a curfew directly; it works by shrinking a daytime exemption. Any source quiet enough to stay under 70 dBA at 25 feet is excused from the Article 4 noise-disturbance rules only between 8 a.m. and 8 p.m. on weekdays and Saturdays, and 10 a.m. to 6 p.m. on Sundays and holidays. Outside those windows, meaning every night, plus Sunday and holiday mornings, that exemption disappears and the full Chapter 9.40 limits apply in full force: the 10 dBA residential cap, 12 dBA commercial/industrial cap, and the general ban on any 'noise disturbance,' whichever is stricter for the source in question.
Violations & Fines
Making noise above 70 dBA at 25 feet outside the daytime exemption window is enforceable as a misdemeanor under the Code's general penalty chapter, up to $1,000 and six months, or as an infraction.
Frequently Asked Questions
Does Union City have a nighttime noise curfew?
What's the noise threshold during the day in Union City?
Sources & Official References
Other rules in Union City
How Union City compares: Cities with the Strictest Noise Ordinances·California rules heatmap·Compare Union City to another location·View the California noise ordinances overview
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Quiet Hours in Nearby Cities
How other cities in Alameda County handle quiet hours.