Hillsboro, OR Noise from Specific Sources: Car Alarm Limits (2026)
Key Facts
- Governing section
- HMC 6.24.050(C)
- Exempt
- bona fide alarm system sounds
- Base noise limit
- 50-70 dBA by zone
- Chronic false alarms
- handled as nuisance, HMC 6.28
Summary
Hillsboro's noise ordinance exempts bona fide alarm systems, including vehicle alarms, from the city's decibel limits, so a car alarm sounding as genuine theft protection isn't a code violation on its own.
Sounds caused by bona fide use of emergency warning devices and alarm systems.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Supplement 1 | Community Development Code: Supplement 1).
Full Breakdown
HMC 6.24.030 sets zone-based decibel limits (50-70 dBA depending on zone and time of day) and 6.24.040 lists specific violations, but 6.24.050(C) carves out 'bona fide use of emergency warning devices and alarm systems' as an exception to the whole noise subchapter. A car alarm triggered by an actual break-in attempt falls under that exception. Separately, sounding a horn while a vehicle is in motion (other than as a danger signal) is its own violation under 6.24.040(A) and isn't covered by this exemption.
Violations & Fines
No citation issues for a car alarm sounding as bona fide theft protection; a chronic false or malfunctioning alarm can instead be pursued as a public nuisance under HMC Chapter 6.28.
Frequently Asked Questions
Can I be fined for my car alarm going off in Hillsboro?
What if my car alarm keeps going off and won't stop?
Sources & Official References
Other rules in Hillsboro
Compare Hillsboro to another location·View the Oregon noise from specific sources overview
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Car Alarm Limits in Nearby Cities
How other cities in Washington County handle car alarm limits.