Decibel Limits: Altadena vs Downey
How do decibel limits rules compare between Altadena, CA and Downey, CA?
Altadena and Downey have similar restriction levels.
Altadena, CA
Los Angeles County
Exterior noise in Altadena's residential zones is capped at 50 dBA daytime / 45 dBA nighttime (single-family); 55/50 dBA (multi-family); 60/55 dBA commercial; 70 dBA all hours industrial.
View full Altadena rules →Downey, CA
Los Angeles County
Downey Municipal Code Section 4600 establishes noise standards. Any noise exceeding 100 decibels at 25 feet or more from the source is a prima facie violation. Power tools and equipment in residential zones are restricted between 10 PM and 7 AM.
View full Downey rules →Key Facts Comparison
| Fact | Altadena | Downey |
|---|---|---|
| Code Section | LA County 12.08.390 | DMC §4600 |
| R-1 Day Limit | 50 dBA | - |
| R-1 Night Limit | 45 dBA | - |
| Multi-family Day/Night | 55 / 50 dBA | - |
| Commercial Day/Night | 60 / 55 dBA | - |
| Prima Facie Limit | - | 100 dBA at 25 ft |
| Restricted Hours | - | 10 PM–7 AM (residential zones) |
| Applies To | - | R-1, R-2, R-3 zones |
| Enforcement | - | Downey PD: (562) 861-0771 |
Highlighted rows indicate differences between cities.
Altadena FAQ
What's the legal decibel limit at my Altadena property line?
50 dBA day / 45 dBA night for single-family residential under LA County Code 12.08.390.
Downey FAQ
What are Downey's noise limits?
Any noise exceeding 100 decibels at 25 feet from the source is a prima facie violation under Section 4600. Power equipment in residential zones is restricted between 10 PM and 7 AM.
Can I use power tools at night in Downey?
No. Power tools, machines, and equipment may not be used in residential zones (R-1, R-2, R-3) between 10 PM and 7 AM if the noise disturbs neighbors.
Compare other topics
See how Altadena and Downey compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool