Jefferson County, CO Noise Ordinances: Decibel Limits (2026)
Key Facts
- Residential limit
- 55 dB(A) day / 50 dB(A) night
- Industrial limit
- 80 dB(A) day / 75 dB(A) night
- Measurement point
- 25 feet from property line
- Daytime spike allowance
- +10 dB(A) for up to 15 minutes/hour
- Impulsive/shrill noise penalty
- Treated as nuisance at -5 dB(A)
Summary
Colorado's Noise Abatement Act sets hard decibel ceilings by zone in unincorporated Jefferson County: 55 dB(A) daytime and 50 dB(A) nighttime in residential areas, rising to 80/75 dB(A) in industrial zones. Exceeding the limit at the property line is prima facie evidence of a public nuisance.
(1) Every activity to which this article is applicable shall be conducted in a manner so that any noise produced is not objectionable due to intermittence, beat frequency, or shrillness. Sound levels of noise radiating from a property line at a distance of twenty-five feet or more therefrom in excess of the db(A) established for the following time periods and zones shall constitute prima facie evidence that such noise is a public nuisance: Zone / 7:00 a.m. to next 7:00 p.m. / 7:00 p.m. to next 7:00 a.m. Residential 55 db(A) / 50 db(A). Commercial 60 db(A) / 55 db(A). Light industrial 70 db(A) / 65 db(A). Industrial 80 db(A) / 75 db(A). (2) In the hours between 7:00 a.m. and the next 7:00 p.m., the noise levels permitted in subsection (1) of this section may be increased by ten db(A) for a period of not to exceed fifteen minutes in any one-hour period. (3) Periodic, impulsive, or shrill noises shall be considered a public nuisance when such noises are at a sound level of five db(A) less than those listed in subsection (1) of this section.
Full Breakdown
): residential 55/50 dB(A), commercial 60/55 dB(A), light industrial 70/65 dB(A), and industrial 80/75 dB(A). Subsection (2) allows a 10 dB(A) daytime spike for up to 15 minutes in any one-hour period, covering short bursts like a delivery truck backing up or a lawn crew starting equipment. Subsection (3) treats periodic, impulsive, or shrill noise as a nuisance at a level 5 dB(A) below the base table, so a repetitive banging or whine is judged more strictly than steady sound. Subsection (5) puts construction projects at the industrial-zone ceiling (80/75 dB(A)) for the life of the permit.
Railroad rights-of-way are deemed industrial zones under subsection (6). The statute exempts aircraft, sanctioned speed/endurance events, snowmaking, government-sponsored cultural and athletic events including fireworks displays, and utility noise reviewed by the Public Utilities Commission. Jefferson County's own Noise Abatement Policy (Part 3, Ch. 1, Sec. 1), adopted by Resolution CC07-202 and administered by the Sheriff's Office, tracks these same zone thresholds for local enforcement.
Violations & Fines
A county or any resident may sue in Jefferson County District Court under § 25-12-104 to enjoin a noise nuisance; violating an injunction is punishable as contempt of court under § 25-12-105. Locally, the Sheriff's Office cites excess noise as a Class 2 Petty Offense under the county's own Noise Abatement Policy, carrying a $30 fine that climbs $30 per repeat offense up to a $300 cap.
Frequently Asked Questions
What decibel limit applies to a house in unincorporated Jefferson County?
Is a brief loud noise, like a delivery, still a violation?
Who enforces the noise limit and what happens if I'm cited?
Sources & Official References
Other rules in Jefferson County
Compare Jefferson County to another location·View the Colorado noise ordinances overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.