Thurston County, WA Noise from Specific Sources: Generator Noise (2026)
Key Facts
- Daytime limit (7am-10pm)
- 55 dBA at adjacent property
- Nighttime limit (10pm-7am)
- 45 dBA at adjacent property
- Power-outage exemption
- Generators exempt during actual outages
- Measurement standard
- WAC 173-58 procedures
- Violation classification
- Misdemeanor or civil penalty
- Who may complain
- Only affected resident or property owner
Summary
Thurston County caps gas and diesel generator noise at 55 dBA from 7 a.m. to 10 p.m. and 45 dBA overnight, measured at the nearest property line or public right-of-way, under County Code Section 10.36.030(C). Section 10.36.040(I) exempts generators run during an actual power outage, so the daytime and nighttime limits apply only to routine, non-emergency generator use.
It is unlawful for any person willfully to cause, or any person in possession of property willfully to allow to originate from the property, any sound which: ... C.Is caused by the operation of either a gas or diesel powered generator that exceeds fifty-five dBA between the hours of seven a.m. and ten p.m. and forty-five dBA between the hours of ten p.m. and seven a.m., measured at any adjacent parcel or public right-of-way; ... I.Sounds created by the use of a generator during power outages.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Code of Ordinances: Supplement 77).
Full Breakdown
020's declaration of special conditions. , measured at any adjacent parcel or public right-of-way. 035. Only a person who resides or owns property in the affected area may file the complaint that triggers enforcement. 040(I) carves out one exemption: sounds created by using a generator during an actual power outage are not covered by the chapter at all, so a homeowner running a backup generator during a storm-driven outage is not exposed to the daytime and nighttime dBA caps, no matter how loud the unit runs or how long the outage lasts. 38 rather than a criminal charge for the same conduct.
Violations & Fines
Running a gas or diesel generator above 55 dBA in the daytime or 45 dBA overnight, measured at the nearest property line, is a misdemeanor under Section 10.36.050 unless the power-outage exemption in Section 10.36.040(I) applies. Thurston County may instead issue a civil penalty notice under Chapter 10.38 for the same violation, and only a neighboring resident or property owner can file the underlying noise complaint.
Frequently Asked Questions
Is there a decibel limit for portable generators in Thurston County?
Can I run a generator during a power outage without breaking the noise law?
Who enforces Thurston County's generator noise limit?
Sources & Official References
Other rules in Thurston County
Compare Thurston County to another location·View the Washington noise from specific sources overview
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