Santa Clara County, CA Noise from Specific Sources: Car Alarm Limits (2026)
Key Facts
- Time limit
- 15 minutes to terminate
- Testing hours
- 7am-7pm only
- Applies to
- Unincorporated county only
Summary
In unincorporated Santa Clara County, a motor vehicle burglar alarm that doesn't shut off within 15 minutes of activation is a noise-code violation.
Sounding or permitting the sounding of any exterior burglar or fire alarm or any motor vehicle burglar alarm unless the alarm is terminated within 15 minutes of activation.(11)Domestic power tools.a.Operating or permitting the operation of any mechanically powered saw, sander, drill, grinder, lawn or garden tool, or similar tool between 10:00 p.m. and 7:00 a.m. the following day so as to create a noise disturbance across a residential or commercial real property line.b.Any motor, machinery or pump will be sufficiently enclosed or muffled and maintained so as not to create a noise disturbance in accordance with Section B11-152.(12)Air-conditioning or air-handling equipment. Operating or permitting the operation of any air-conditioning or air-handling equipment in a manner as to exceed any of the following sound levels without a variance: Measurement Location; dB(A)
Any point on neighboring property line, five feet above grade level, no closer than three feet from any wall .....50
Center of neighboring patio, five feet above grade level, no closer than three feet from any wall .....45
Outside the neighboring living area window nearest the equipment location, not more than three feet from the window opening, but at least three feet from any other surface .....45
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 65).
Full Breakdown
Ordinance Code § B11-154(10)(c) makes it a prohibited act to sound or permit the sounding of an exterior burglar or fire alarm, or a motor vehicle burglar alarm, unless it terminates within 15 minutes of activation. The rule sits inside the county's noise-disturbance chapter, which separately allows stationary emergency signaling devices to be tested only between 7 a.m. and 7 p.m. under § B11-154(10)(b). It reaches only unincorporated Santa Clara County; inside San Jose, Sunnyvale, Palo Alto and the county's other cities, each municipal noise code controls car alarms instead.
Violations & Fines
A car alarm running past the 15-minute mark is a code violation the county can pursue as a nuisance; knowingly defying a resulting court injunction is a misdemeanor punishable by up to $500 and five days in jail.
Frequently Asked Questions
Does the 15-minute rule also cover home burglar alarms?
What if my car alarm goes off inside San Jose?
Sources & Official References
Other rules in Santa Clara County
California rules heatmap·Compare Santa Clara County to another location·View the California noise from specific sources overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.