Noise Ordinances in Boulder County, CO (2026)
8 county-level rules, plus city-specific rules for 2 cities in Boulder County, Colorado.
Verified from official government sources
Quiet Hours
Non-vehicle noise in unincorporated Boulder County residential areas is capped at 55 dB(A) from 7 a.m. to 7 p.m., dropping to 50 dB(A) overnight, under Ordinance No. 92-28 Sec. 1.01.050(C). Lawnmowers, snowblowers and hand tools of 5 horsepower or less are exempt between 7 a.m. and 10 p.m.
Boulder County Nighttime Quiet Hours
Some RestrictionsBoulder County Ordinance No. 92-28, Sec. 1.01.050(C)
SECTION 1.01.050 Prohibited Noise Levels. C. Sound from a non-vehicular source located in a residential area, shall not exceed the following limits: 7:00 a.m.-7 p.m. of the same day: 55 dB(A) 7:00 p.m.-7 a.m. of the following day: 50 dB(A) E. Periodic, impulsive, or shrill noises are hereby declared unlawful when such noises are at or above a sound level of five dB(A) less than those liste...
Construction Hours
Construction noise in residential areas of unincorporated Boulder County is capped at 80 dB(A) from 7 a.m. to 7 p.m. and drops to 75 dB(A) overnight, under Ordinance No. 92-28 Sec. 1.01.050(D). The stricter overnight cap runs for the whole life of the project's construction permit, or a reasonable completion period if none was set.
Boulder County Construction Noise Hour Limits
Some RestrictionsBoulder County Ordinance No. 92-28, Sec. 1.01.050(D)
SECTION 1.01.050 Prohibited Noise Levels. D. Construction projects in residential areas shall not exceed the following noise levels for the period within which construction is to be completed pursuant to any applicable construction permit issued by Boulder County, or if no time limitation is imposed, then for a reasonable period of time for completion of project: 7:00 a.m.-7:00 p.m. of the s...
Barking Dogs
Boulder County's decibel-based noise ordinance, No. 92-28, caps residential sound at 55 dB(A) by day and 50 dB(A) at night under Section 1.01.050(C), but Section 1.01.060(I) expressly excepts "the sound made by animals" from that limit and from the general rules in Sections 1.01.030, 1.01.040 and 1.01.050. Barking is policed separately, under the county's Animal Control Ordinance.
Barking Dogs Are Exempt From Boulder County Noise Law
Some RestrictionsBoulder County Ordinance No. 92-28, Sec. 1.01.060(I); Sec. 1.01.050(C)
The provisions of Sections 1.01.030, 1.01.040 and 1.01.050 of this ordinance shall not apply to: ... I. The sound made by animals. ... Sound from a non-vehicular source located in a residential area, shall not exceed the following limits: 7:00 a.m.-7 p.m. of the same day: 55 dB(A); 7:00 p.m.-7 a.m. of the following day: 50 dB(A).
Leaf Blower Rules
Unincorporated Boulder County exempts leaf blowers, lawnmowers, snowblowers, and other hand or power tools of 5 horsepower or less from noise limits when used between 7 a.m. and 10 p.m. Outside those hours, general noise limits apply.
Leaf Blowers and Power Tools in Boulder County
Some RestrictionsBoulder County Ordinance No. 92-28, Sec. 1.01.060(L)
The sound made by a lawnmower, snowblower, or other hand or power tool of no more than five horsepower, between the hours of 7 a.m and 10 p.m.
Amplified Music & Outdoor Sound
Boulder County treats amplified music from a parked or non-moving vehicle as noise from a fixed source, measured 10 feet from the property line, and caps residential noise at 55 dB(A) by day and 50 dB(A) overnight. Violations are a Class 2 Petty Offense with fines climbing from $30 to $300.
Amplified Music and Noise Limits in Boulder County
Some RestrictionsBoulder County Ordinance No. 92-28, Sections 1.01.040(C) & 1.01.050(C)
C. Sound from a non-vehicular source shall be measured at a distance of ten feet from the property line of the property where such sound is radiating, except that where the noise source is located on public property owned by a governmental entity, the sound shall be measured at a distance of ten feet from the property line or fifty feet from the noise source, whichever is less. The sound of amp...
Aircraft Noise
Boulder County's noise ordinance does not regulate aircraft. Section 1.01.060(G) exempts "operation of aircraft or other activities which are subject to federal law with respect to noise control," leaving airplane and helicopter noise to the FAA.
Aircraft Noise in Boulder County
Some RestrictionsBoulder County Ordinance No. 92-28, Sec. 1.01.060(G)
The provisions of Sections 1.01.030, 1.01.040 and 1.01.050 of this ordinance shall not apply to: ... G. Operation of aircraft or other activities which are subject to federal law with respect to noise control.
Decibel Limits
Boulder County caps vehicle noise on unincorporated roads at 80 dB(A) (84 dB(A) above 35 mph) for most vehicles, with higher ceilings for heavy trucks and older motorcycles, under Ordinance No. 92-28 Sec. 1.01.050. Vehicles on private property or off-road are held to a flat 78 dB(A), and impulsive or shrill sounds trip a 5 dB(A) stricter threshold.
Boulder County Vehicle Noise Decibel Limits
Some RestrictionsBoulder County Ordinance No. 92-28, Sec. 1.01.050(A), (B), (E)
SECTION 1.01.050 Prohibited Noise Levels. A. Sound from a vehicle being operated on a public road or highway with the following speed limits shall not exceed the following as measured on the "A" weighting scale dB(a): Motorcycle manufactured before 1/1/1973 82 dB(A) 86 dB(A); Motorcycle manufactured on or after 1/1/1973 80 dB(A) 84 dB(A); Vehicle with a manufacturer's gross vehicle rating of ...
Vehicle Noise
Every vehicle operated in unincorporated Boulder County must run a muffler in constant operation and properly maintained, under Ordinance No. 92-28 Sec. 1.01.070. Cutting out, bypassing, or otherwise modifying a muffler to increase noise is separately banned under Sec. 1.01.080, on top of the ordinance's numeric dB(A) ceilings for vehicles on roads and private property.
Boulder County Muffler and Vehicle Noise Rules
Some RestrictionsBoulder County Ordinance No. 92-28, Sec. 1.01.070 & 1.01.080
SECTION 1.01.070 Vehicle Muffler Required. A. No person shall operate anywhere in unincorporated Boulder County any vehicle that is not equipped with a muffler in constant operation. B. No person shall operate any vehicle in which a muffler is not properly maintained to prevent any noise in excess of the noise emitted when the muffler was originally installed by the manufacturer of the vehic...
Noise Ordinances by City in Boulder County
2 cities in Boulder County have their own noise ordinances rules. Each link goes to that city's dedicated page with code citations.
All Boulder County ordinances
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