Noise Ordinances in Thornton, CO (2026)
6 verified noise ordinances for Thornton, Colorado, sourced directly from the municipal code and official government pages.
Verified from official government sources
Quiet Hours
Thornton restricts bells and chimes to the hours of 7:00 a.m. to 10:00 p.m.; running them between 10:00 p.m. and 7:00 a.m. in violation of Table A's decibel limits is a noise violation. The city can also post conspicuous signs declaring a "quiet zone" around schools, churches, courthouses, hospitals, and nursing homes.
Thornton Nighttime Quiet Hours and Quiet Zones
Some RestrictionsThornton City Code § 38-441(a)(3)a, (a)(4), (b)(2)
a.Bells and chimes or any device for the production or reproduction of the sound of bells or chimes operated between the hours of 10:00 p.m. of one day and 7:00 a.m. of the following day and is in violation of the sound level standards contained in subsection (c), Table A herein... (2)Bells and chimes or any device for the production or reproduction of the sound of bells or chimes from any chur...
Construction Hours
Thornton bans construction activity noise citywide between 9:00 p.m. and 6:00 a.m., except in industrial districts or on priority-review projects at least 400 feet from an occupied home. Daytime construction between 6:00 a.m. and 9:00 p.m. must still meet the industrial-district sound limit under § 38-441(c)(5).
Thornton Construction Noise Hours Restriction
Some RestrictionsThornton City Code § 38-441(c)(5)
(5)Construction activities as defined in Section 38-1 are subject to the following requirements:a.Construction activities are prohibited within any zoning district between the hours of 9:00 p.m. and 6:00 a.m. unless specifically authorized in paragraph (5)c or (5)d, below.b.Construction activities occurring between 6:00 a.m. and 9:00 p.m. shall comply with the sound pressure level limits for in...
Barking Dogs
Thornton makes it a noise violation for any animal or bird to create a plainly audible sound through frequent or habitual howling, barking, yelping, meowing, squawking or squealing. Code compliance officers and police enforce it under § 38-441(a)(3)d, the same section covering all disruptive neighborhood noise.
Thornton Barking Dog and Animal Noise Rule
Some RestrictionsThornton City Code § 38-441(a)(3)d
(3)In addition to subsection (a)(1), the following are declared to be noises or sounds which by their sound level and duration disturb, or tend to disturb, the repose of the community and which shall constitute a violation of this subsection (a)(3)... d.Any animal or bird which by frequent or habitual howling, barking, yelping, meowing, squawking, squealing or other noise, creates a plainly aud...
Amplified Music & Outdoor Sound
Thornton bars any loudspeaker, PA system, or device that transmits music, instructions, or announcements if the resulting noise is plainly audible across a residential property line. Operators in commercial zones or at city-sponsored events must first get a temporary sound-amplification permit from the city clerk, valid only 7:30 a.m. to 10:00 p.m.
Thornton Amplified Sound and Music Permit Rules
Significant RestrictionsThornton City Code § 38-441(a)(3)b, (c)(10)
b.The use or operation of any type of audio or video system, noisemaker or loudspeaker or public address system operated or used on public or private property for any purposes including, but not limited to, vending, advertising, announcements or notifications, or any device used for transmitting music or for giving instructions, talks or lectures to any assembly of persons which results in a no...
Decibel Limits
Thornton caps continuous sound at 55 dB(A) by day and 50 dB(A) by night in residential districts, 60/55 dB(A) in other nonresidential districts, and 80/75 dB(A) in industrial districts, measured at the property line under Table A of § 38-441(c).
Thornton Numeric Decibel Limits by District
Some RestrictionsThornton City Code § 38-441(c)(2), Table A
(2)The maximum permissible sound pressure levels of any continuous source of sound is given in subsection (c), Table A, Sound Pressure Level Limits. Sound pressure levels in excess of the limits for the district in which the source is located are considered an unreasonable noise and are prohibited. Table A. Sound Pressure Level Limits District dB(A) During the Day, 7:00 a.m. to 7:00 p.m. dB(A) ...
Vehicle Noise
Thornton requires every vehicle to run a working muffler, with no cutoff, bypass, or similar modification, and caps drive-by vehicle noise at 80 dB(A) for vehicles under 6,000 pounds and 88 dB(A) for heavier vehicles under § 38-441(a)(3)e and (c)(8). Violations bring an immediate summons rather than a notice to abate.
Thornton Vehicle Muffler and Exhaust Noise Limits
Some RestrictionsThornton City Code § 38-441(a)(3)e, (c)(8)
e.Any steam engine, stationary internal combustion engine, air compressor, motorboat, motor vehicle or other power device which is not equipped with a muffler in good working order that is in constant operation and properly maintained and which use is in violation of the sound level standards contained in subsection (c), Table A... No such muffler or exhaust system shall be modified or used wit...
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