Quiet Hours: Altadena vs Norwalk
How do quiet hours rules compare between Altadena, CA and Norwalk, CA?
Altadena and Norwalk 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 →Norwalk, CA
Los Angeles County
Norwalk Article III treats any noise reading exceeding the ambient noise level at a residential property line by more than 5 dBA as prima facie evidence of violation. 'Daytime' is M-F 7 AM-8 PM, Sat 8 AM-8 PM, Sun/holidays 9 AM-8 PM.
View full Norwalk rules →Key Facts Comparison
| Fact | Altadena | Norwalk |
|---|---|---|
| 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 | - |
| Standard | - | Ambient + 5 dBA |
| M-F Daytime | - | 7 AM - 8 PM |
| Saturday | - | 8 AM - 8 PM |
| Sun/Holiday | - | 9 AM - 8 PM |
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.
Norwalk FAQ
How does Norwalk measure a noise violation?
Article III of the Norwalk Municipal Code treats any average noise reading at the residential property line that exceeds the ambient (background) noise level by more than 5 dBA as prima facie evidence of a violation. Officers measure with a sound-level meter.
What hours count as 'daytime' for noise purposes?
Monday-Friday 7 AM to 8 PM; Saturday 8 AM to 8 PM; Sunday and federal/state holidays 9 AM to 8 PM. Outside those windows, the stricter nighttime expectations apply.
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