Altadena's Noise Ordinances: The Rules That Matter

Every city handles noise ordinances a little differently. In Altadena, California, there are 5 distinct rules that residents and property owners should be aware of. Some are stricter than what neighboring cities enforce, and others are more relaxed. Here is what you need to know.

Decibel Limits

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.

Key details: 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.

Citable as an infraction under Section 12.08.560. Administrative fines under Chapter 1.25.

Quiet Hours

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.

Key details: Code Section: LA County Code Ch. 12.08 (Title 12). 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.

Per Section 12.08.560 and Chapter 1.25, violations are infractions or misdemeanors. Administrative citations typically run $100 (first offense), $200 (second within 12 months), and $500 (third), and each day of continuing violation is a separate offense.

Construction Hours

LA County Code Section 12.08.440 limits construction noise in residential areas to 7:00 a.m.–8:00 p.m. weekdays and 8:00 a.m.–8:00 p.m. on Saturdays. No construction is allowed on Sundays or county holidays.

Key details: Code Section: LA County Code 12.08.440. Weekday Hours: 7 a.m. – 8 p.m.. Saturday Hours: 8 a.m. – 8 p.m.. Sunday/Holiday: Prohibited.

Violations are processed as infractions/administrative fines under Chapter 1.25 of the County Code (typically $100, $200, $500 escalating) and each day is a separate violation.

Barking Dogs

LA County Code Section 10.36.010 prohibits owning or keeping any animal that habitually disturbs the peace by barking, howling, or other noise. Enforced by LA County Animal Care & Control.

Key details: Code Section: LA County Code 10.36.010. Enforcement Agency: LA County Animal Care & Control. Classification: Public nuisance / infraction.

Continued barking nuisance can be prosecuted as a misdemeanor under Title 10 with fines up to $1,000 and impoundment in extreme cases.

Leaf Blower Rules

LA County does not have a county-wide gas leaf-blower ban, but operation is subject to the Ch. 12.08 dB limits and construction-hours rules (7 a.m.–8 p.m. weekdays).

Key details: Code Section: LA County Code 12.08.440. Permitted Hours: 7 a.m. – 8 p.m. M-F. Residential dB Cap: 50 dBA daytime / 45 dBA night. Gas Blower Ban: None at county level.

Administrative citations under Chapter 1.25 — typically $100, $200, $500 escalating.

The Bottom Line

Altadena's noise ordinances rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Altadena is broadly strict or permissive.

These rules come from Altadena's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.