Simi Valley, CA Noise from Specific Sources: Generator Noise (2026)
Key Facts
- Weeknight curfew
- 10:00 p.m.-7:00 a.m., Sunday-Thursday
- Weekend curfew
- 11:00 p.m.-7:00 a.m., Friday-Saturday
- Audibility threshold
- Not plainly audible 50 feet from enclosure
- Residence buffer
- 10 feet minimum without sound insulation
- Public roadway vehicles
- Excluded from this subsection
- Penalty
- Misdemeanor, separate offense per day
Summary
Simi Valley Municipal Code Section 5-16.02(d) bars running a portable generator, motor or engine outdoors between 11 p.m. and 7 a.m. on weekends and 10 p.m. and 7 a.m. on weeknights unless it sits inside a sound-insulated enclosure quiet enough that it can't be heard 50 feet away, or is more than 10 feet from a residence.
(d)Engines, motors, and mechanical devices in and near residential districts. The operation between the hours of 11:00 p.m. and 7:00 a.m. on Friday or Saturday and between the hours of 10:00 p.m. and 7:00 a.m. on Sunday through Thursday of any motor or engine or the use or operation of any automobile, motorcycle, machine, mechanical device, or other contrivance or facility, unless such motor, engine, automobile, motorcycle, machine, or mechanical device is enclosed within a sound-insulated structure so as to prevent noise and sounds from being plainly audible at a distance of fifty (50′) feet from such structure or within ten (10′) feet of any residence; provided, however, any such vehicle which is operated upon any public highway, street, or right-of-way shall be excluded from the provisions of this subsection;
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 51).
Full Breakdown
02 of the Noise chapter declares a list of public nuisances, and subsection (d), "Engines, motors, and mechanical devices in and near residential districts," targets exactly the generator-and-engine noise homeowners run into during power outages, construction, and yard work. window Sunday through Thursday. Inside that window, running a motor, engine, or other mechanical device is unlawful unless it's enclosed in a sound-insulated structure quiet enough that noise isn't "plainly audible" 50 feet from the structure, or the source sits more than 10 feet from the nearest residence.
The subsection carves out one specific exception: any vehicle actually being driven on a public highway, street, or right-of-way is excluded, so this rule reaches stationary equipment, a backup generator, a compressor, a running truck engine parked in a driveway, rather than passing traffic. It sits alongside the chapter's other nighttime-only limits: subsection (b) covers radios and amplified sound, subsection (c) covers band rehearsals within 200 feet of a home, and subsection (a) is the catchall for any other loud, unnecessary or unusual noise that disturbs a neighbor of ordinary sensitivity. 02 opens by declaring these acts nuisances, with each maintained or permitted nuisance charged as a misdemeanor for every day it continues.
Violations & Fines
Anyone maintaining or permitting a nuisance under Section 5-16.02, including running a generator or engine past the curfew without adequate sound insulation, shall be deemed guilty of a misdemeanor for each day during which such nuisance is maintained or permitted to exist, per the section's opening language, meaning repeated nights of violation can be charged separately rather than as one continuing offense.
Frequently Asked Questions
Can I run a backup generator overnight during a power outage in Simi Valley?
Does this rule cover construction equipment too?
Is my car engine idling in the driveway covered?
Sources & Official References
Other rules in Simi Valley
California rules heatmap·Compare Simi Valley to another location·View the California noise from specific sources overview
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