Decibel Limits: Altadena vs Carson
How do decibel limits rules compare between Altadena, CA and Carson, CA?
Altadena and Carson 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 →Carson, CA
Los Angeles County
Carson Municipal Code Art. 4 Ch. 5 adopts LA County Code Title 12 Ch. 12.08 by reference. Section 12.08.390 sets exterior decibel standards by Noise Zone (defined in §12.08.380). Residential (Zone I): 50 dBA daytime 7 a.m.–10 p.m. / 45 dBA nighttime 10 p.m.–7 a.m. Commercial (Zone II): 65 dBA day / 60 dBA night. Industrial (Zone III): 70 dBA at all hours. The standards are measured at the property line of the receiving property. Graduated exceedance allowances (§12.08.390): base standard for 30+ min/hour; +5 dBA for 15–30 min/hr; +10 dBA for 5–15 min/hr; +15 dBA for 1–5 min/hr; +20 dBA for less than 1 min/hr; never above ambient + 20 dBA in any case. If the ambient L50 already exceeds the table value, ambient L50 becomes the baseline. Plainly-audible-from-100-feet (residential) and similar nuisance standards under §12.08.560 also apply for amplified sound, animals, and parties.
View full Carson rules →Key Facts Comparison
| Fact | Altadena | Carson |
|---|---|---|
| Code Section | LA County 12.08.390 | - |
| 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 | - |
| Residential exterior limit | - | 50 dBA day (7a–10p) / 45 dBA night (10p–7a) |
| Commercial exterior limit | - | 65 dBA day / 60 dBA night |
| Industrial exterior limit | - | 70 dBA all hours |
| Multi-family interior limit | - | 45 dBA day / 40 dBA night |
| Measurement standard | - | ANSI Type 1/2 SLM, A-weighted, slow response (§12.08.220) |
| Construction hours | - | 7 a.m.–7 p.m. weekdays; no Sunday/holiday (§12.08.440) |
| Maximum exceedance | - | +20 dBA for less than 1 min/hr; +15 dBA for 1–5 min/hr |
| Penalty range | - | Up to $1,000 + 6 mo jail (LA Co. §12.08.030) / Carson admin $100–$500 |
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.
Carson FAQ
What is Carson's nighttime residential noise limit?
45 dBA between 10 p.m. and 7 a.m., measured at your property line — per LA County Code §12.08.390 (Noise Zone I), adopted by Carson Municipal Code Art. 4 Ch. 5.
Do I need a sound level meter to file a noise complaint?
No. While the formal standard is a measured dBA reading, Carson Code Enforcement and the LA County Sheriff's Carson Station respond to plainly-audible-from-50-feet violations and may issue citations based on officer observation under LA County Code §12.08.560 (amplified sound) and §12.08.570 (animal noise).
What if my neighbor's stereo is loud but only for 5 minutes at a time?
Short-duration loud noise is still regulated by a graduated table — +15 dBA above the standard is allowed for 1–5 minutes per hour, but not more. Sustained amplified sound audible at 50 ft in a residential zone is a per se violation regardless of duration.
Are emergency generators and HVAC equipment regulated?
Yes — stationary mechanical equipment must comply with the property-line dBA limits. Carson's Building Code (CMC Art. 4) and CALGreen Title 24 Part 11 §5.507 also require noise attenuation for new commercial HVAC located near residential.
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