King County, WA Noise Ordinances: Quiet Hours (2026)
Quiet hours in King County, WA, also called the noise ordinance, nighttime noise rules, or residential quiet time, define the hours during which excessive noise is prohibited.
Key Facts
- Weekday quiet hours
- 10 p.m.–7 a.m.
- Weekend quiet hours
- 10 p.m.–9 a.m.
- Nighttime reduction
- 10 dB(A) lower limit
- First-offense fine
- up to $125
- Applies to
- unincorporated King County only
Summary
Unincorporated King County tightens its noise limits at night: allowed sound levels drop by 10 dB(A) from 10 p.m. to 7 a.m. on weekdays and 10 p.m. to 9 a.m. on weekends in rural and residential areas.
Between 10:00 p.m. and 7:00 a.m. during weekdays, and between 10:00 p.m. and 9:00 a.m. on weekends, the levels established by K.C.C. 12.86.110 are reduced by 10 dB(A) where the receiving property lies within a rural or residential district of King County. The following sounds are exempt from this subsection:
1. Sounds created by existing stationary equipment used in the conveyance of water by a utility; and
2. Sounds created by electrical substations;
B. For any source of sound that has a pure tone component, the levels established by this chapter shall be reduced by 5 dB(A), but this reduction shall not be imposed on any electrical substation. For the purposes of this subsection, ["pure tone component" means sound having the following qualities: a one-third octave band sound pressure level in the band with the tone that exceeds the arithmetic average of the sound pressure levels of the two contiguous one-third octave bands by 5 decibels for center frequencies of 500 Hz and above, by 8 decibels for center frequencies between 160 and 400 Hz, and by 15 decibels for center frequencies less than or equal to 125 Hz]*; and
C. For any source of sound that is impulsive and not measured with an impulse sound level meter, the levels established by this chapter are reduced by 5 dB(A). (Ord. 18000 § 51, 2015: Ord. 14114 § 7, 2001: Ord. 3139 § 303, 1977. Formerly K.C.C. 12.88.030).
Full Breakdown
K.C.C. 12.86.120.A automatically reduces the county's baseline environmental sound-level limits (set in 12.86.110, ranging 49-70 dB(A) by source and receiving-property district) by 10 dB(A) overnight: 10:00 p.m. to 7:00 a.m. on weekdays, and 10:00 p.m. to 9:00 a.m. on weekends, whenever the receiving property is in a rural or residential district. Existing water-utility conveyance equipment and electrical substations are exempt from this nighttime reduction. This applies only in unincorporated King County; Seattle, Bellevue, Kent, Renton, Auburn, Redmond, Kirkland and other cities enforce their own municipal noise codes.
Violations & Fines
First violation within 12 months: civil infraction up to $125. Second: up to $250. Each later violation within the same 12 months: up to double the prior fine, per K.C.C. 12.86.700.
Frequently Asked Questions
Does this cover Seattle?
How much stricter are night limits?
What's the penalty for a repeat violation?
Sources & Official References
Other rules in King County
How King County compares: Cities with the Strictest Noise Ordinances·Compare King County to another location·View the Washington noise ordinances overview
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