Noise Ordinances in Seattle, WA

If you live in Seattle or are thinking about moving there, noise ordinances are one of those things you probably won't think about until they affect you directly. Seattle has 6 specific rules on the books covering different aspects of noise ordinances, and some of them might surprise you.

Vehicle Noise

Seattle requires every motor vehicle to run a working muffler that prevents excessive or unusual noise, and bars cut-out or bypass devices entirely. Heavy trucks using engine ("Jake") compression brakes must keep exhaust noise at 83 dBA or less (80 dBA for post-1988 vehicles) or face escalating fines.

Key details: Muffler rule: Working muffler required; no cut-outs (SMC 11.84.080). Engine brake noise cap (pre-1988): 83 decibels or less. Engine brake noise cap (1988+): 80 decibels or less. First offense fine: $250. Second offense fine: $500.

SMC 11.84.070 sets its own fixed penalty schedule for exceeding the compression-brake noise standard or braking where signs prohibit it: $250 for a first violation, $500 for a second, and $750 for each violation after that. A muffler cut-out, bypass device, or an inoperative/excessively loud muffler under SMC 11.84.080 is a traffic infraction citable by SPD on any street or alley within city limits.

Decibel Limits

Seattle sets numeric exterior noise limits by zoning district under SMC 25.08.410 Table A, ranging from 55 dB(A) between residential properties up to 70 dB(A) for industrial-to-industrial noise, measured as a one-minute or one-hour Leq. Brief peaks (Lmax) may run up to 15 dB(A) above the table's limit before counting as a violation.

Key details: Residential-to-residential limit: 55 dB(A) Leq. Industrial-to-industrial limit: 70 dB(A) Leq. Short-peak allowance: Lmax up to 15 dB(A) over limit. BINMIC shoreline exception: 70 dB(A) within 200 feet of shoreline. First-citation penalty: $150 (SMC 25.08.960).

Exceeding the Table A limit measured at the receiving property line is a violation of SMC 25.08.410, enforced by SDCI. Under SMC 25.08.960, a citation carries $150 for a first violation, $300 for a second, and $600 for a third or subsequent violation; alternatively, the Administrator may pursue civil penalties of up to $1,300 per day under SMC 25.08.800.

Construction Hours

Seattle SMC 25.08 limits construction equipment to 80 dBA measured at the receiving property line, with maximum-noise exemptions during permitted weekday daytime hours. Impact equipment like jackhammers requires noise-reduction measures.

Key details: Code: SMC 25.08.425. Daytime cap: 80 dBA at line. Permitted hours: 7am-10pm weekdays. Variance authority: SDCI Director. Impact tools: Mitigation required.

First violation: warning. Subsequent: $250-$500 per day. Repeat violator: criminal misdemeanor up to $5,000. Stop-work order possible. SDCI variance revocation for noncompliance.

Barking Dogs

SMC 25.08.500.A makes loud, frequent, repetitive, or continuous animal noise an unlawful 'public disturbance noise' in Seattle once a police officer or animal control officer orders it stopped. Owners of a repeat-violator animal, or one whose owner can't be located, face impoundment under SMC Chapter 9.25, and conduct under this section is a crime under SMC 25.08.800.B.

Key details: Governing section: SMC 25.08.500.A, public disturbance noises. Enforcing officers: Police officer or animal control officer. Kennel/shelter exemption: Permitted facilities under SMC Chapter 10.72. Repeat-violator remedy: Animal impounded under SMC Chapter 9.25. Criminal penalty: Up to $500 fine or 6 months jail (SMC 25.08.800.B).

Letting a dog or other animal bark loudly, repeatedly, or continuously so it disturbs a neighbor violates SMC 25.08.500.A once a police officer or animal control officer orders the noise stopped and it continues. SMC 25.08.800.B makes this a crime: a fine up to $500, up to six months in jail, or both, with each day or occurrence a separate offense; a repeat-violator animal can be impounded under SMC Chapter 9.25.

Quiet Hours

Between 10 p.m. and 7 a.m. on weekdays, and 10 p.m. to 9 a.m. on weekends and legal holidays, SMC 25.08.420 cuts Seattle's exterior sound level limits by 10 dB(A) for any noise reaching a residential district: a mandatory quiet-hours reduction layered on top of the Table A limits in SMC 25.08.410.

Key details: Weekday quiet hours: 10 p.m. to 7 a.m.. Weekend/holiday quiet hours: 10 p.m. to 9 a.m.. Nighttime reduction: 10 dB(A) off the Table A limit. Pure-tone add-on reduction: Additional 5 dB(A) (except substations). First-citation penalty: $150 (SMC 25.08.960).

A source that stays within the daytime Table A limit but exceeds it once the mandatory 10 dB(A) nighttime reduction applies violates SMC 25.08.420. SDCI issues citations under SMC 25.08.960: $150 for a first violation, $300 for a second, $600 for a third or subsequent violation, with civil penalties up to $1,300 per day available as an alternative under SMC 25.08.800.

Amplified Music & Outdoor Sound

Outdoor concerts and amplified performances on Seattle public property are capped at a 95 dB(A) one-minute average measured 50 feet from the source. SDCI, Parks, SDOT or Seattle Center can shut a show down once it hits 105 dB(A) for five minutes in any 30-minute window, under SMC 25.08.520.

Key details: Sound limit: 95 dB(A) Leq, 1 minute, at 50 feet. Shutdown trigger: 105 dB(A) for 5 min in any 30 min. Applies to: Outdoor sanctioned musical events only. Who can terminate a show: SDCI, Parks, SDOT, Seattle Center, Police. General civil penalty: Up to $1,300 per day.

Exceeding the 95 dB(A) one-minute limit after the on-site agent has been notified is a separate offense for each recurrence; hitting 105 dB(A) for five minutes in any 30-minute span lets city officials shut the performance down on the spot. Violations otherwise fall under SMC 25.08.800's general civil penalty of up to $1,300 per day, and permit conditions or required sound monitoring can be imposed before the event even starts.

The Bottom Line

Seattle'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 Seattle is broadly strict or permissive.

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