Quiet Hours: Altadena vs Downey
How do quiet hours rules compare between Altadena, CA and Downey, CA?
Altadena and Downey have similar restriction levels.
Altadena, CA
Los Angeles County
Altadena is unincorporated, so LA County Title 12 Chapter 12.08 (Noise Control) applies. Nighttime exterior limits run 10:00 p.m. to 7:00 a.m. with stricter dB caps; daytime runs 7:00 a.m. to 10:00 p.m.
View full Altadena rules →Downey, CA
Los Angeles County
Downey enforces quiet hours from 10 PM to 7 AM in residential zones under Municipal Code Section 4600. Power tools, machinery, and equipment creating disturbing noise are prohibited during these hours.
View full Downey rules →Key Facts Comparison
| Fact | Altadena | Downey |
|---|---|---|
| Code Section | LA County Code Ch. 12.08 (Title 12) | DMC §4600 |
| Nighttime Window | 10:00 p.m. – 7:00 a.m. | - |
| Residential Night Limit | 45 dBA (R-1) | - |
| Residential Day Limit | 50 dBA (R-1) | - |
| Ambient Exceedance Rule | +5 dB over ambient | - |
| Quiet Hours | - | 10 PM–7 AM |
| Applies To | - | R-1, R-2, R-3 residential zones |
| Vehicle Repair | - | Prohibited when disturbing in residential areas |
| Enforcement | - | Downey PD: (562) 861-0771 |
Highlighted rows indicate differences between cities.
Altadena FAQ
What are Altadena's quiet hours?
10 p.m. to 7 a.m. under LA County Code Ch. 12.08 — Altadena is unincorporated so LA County's noise ordinance applies.
How loud can my backyard be at night?
Single-family residential exterior noise is capped at 45 dBA from 10 p.m. to 7 a.m. per Section 12.08.390.
Downey FAQ
What are Downey's quiet hours?
Quiet hours are 10 PM to 7 AM in residential zones. Power tools, machinery, amplified music, and other noise-producing activities are prohibited during these hours if they disturb neighbors.
Can I fix my car at night in Downey?
Motor vehicle repair or testing that produces disturbing sounds is prohibited in residential areas or within 100 feet of residential zones, especially during quiet hours.
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