Jefferson County, CO Noise Ordinances: Quiet Hours (2026)

The county Noise Abatement Regulation (Adopting Resolution CC07-202, effective April 24, 2007; references C.R.S. 25-12-101 and C.R.S. 16-2-201) establishes maximum permissible noise levels by zone for unincorporated Jefferson County. For non-vehicular sources in a residential zone, the limits are 55 dB(A) from 7:00 a.m. to 7:00 p.m. and 50 dB(A) from 7:00 p.m. to 7:00 a.m., measured 25 feet from the property line on the A-weighting scale. Construction projects in residential zones operating under a valid permit may emit up to 80 dB(A) during the day and 75 dB(A) at night while the permit is in force. Vehicles operating on private property (not a road) may not exceed 78 dB(A) measured 25 feet from the nearest dwelling. Periodic, impulsive, or shrill noises are unlawful when at or above a level 5 dB(A) less than those listed. Exceptions include permitted speed events, machine-made snow operations, public utilities, oil and gas operations, emergency vehicles, fireworks-permit displays, animal sounds, and warning horns. The regulation also requires every vehicle in unincorporated Jefferson County to operate with a properly maintained muffler; cutoff/bypass devices and muffler modifications are prohibited. The Policy Custodian is the Sheriff's Office, which enforces complaints. Cities within Jefferson County (Lakewood, Arvada, Wheat Ridge, Golden, Westminster, Edgewater, Lakeside, Morrison, Mountain View) operate under their own municipal noise codes inside city limits.