Boulder, CO Noise Ordinances: Decibel Limits (2026)
Key Facts
- Residential limit
- 55 dBA day, 50 dBA night
- Mixed-use/commercial limit
- 65 dBA day, 60 dBA night
- Industrial limit
- 80 dBA day, 75 dBA night
- Night hours
- 11 p.m. to 7 a.m.
- Meter standard
- ANSI S1.4-1974 Type I or II
- Governing section
- Boulder Revised Code § 5-9-3
- Variance option
- City manager may grant hardship variance
Summary
Boulder Revised Code § 5-9-3 sets fixed decibel ceilings by the zoning district where sound lands: 55 dBA by day and 50 dBA at night on residential property, 65/60 dBA on mixed-use and commercial land, and 80/75 dBA on industrial land. The night limit runs 11 p.m. to 7 a.m.; the day limit covers 7 a.m. to 11 p.m.
(a)No person shall: (1)Operate any type of vehicle, machine, or device; (2)Carry on any activity; or (3)Promote or facilitate the carrying on of any activity, which makes sound in excess of the level specified in this section. (b)Sound from any source, other than a moving vehicular source located within the public right of way, shall not exceed any of the following limits for its appropriate zone... Residential: 55 dBA (7 a.m. to 11 p.m.), 50 dBA (11 p.m. to 7 a.m.). Mixed use and other: 65 dBA, 60 dBA. Industrial: 80 dBA, 75 dBA.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: Municipal Code: Supplement 167 Update 3).
Full Breakdown
The limit that applies to a sound source is determined by the zoning of the property on which the sound is received, not the zoning of the source. and 50 dBA overnight; mixed-use and commercial land (A, BCS, BMS, BC, MU, P, BT, BR, DT) is capped at 65/60 dBA; industrial land (IG, IM, IS, IMS) is capped at 80/75 dBA. 4-1974. Measurement is taken at or inside the property line of the receiving property, or, if the source sits on public property, at least twenty-five feet from the source.
is deemed received in a commercial zone; amplified construction sound never gets that treatment. m. A property owner may also apply to the city manager for a sound level variance under Section 5-9-10 if compliance would cause undue hardship and no reasonable alternative exists.
Violations & Fines
Boulder Revised Code Chapter 5-9 carries no standalone fine schedule, so a decibel violation defaults to the citywide general penalty in Section 5-2-4: up to $2,650 per violation and up to ninety days in jail, or both, with each day of a continuing violation charged separately. Boulder Police and the city manager's noise team investigate complaints and take sound-meter readings to document exceedances before issuing a summons.
Frequently Asked Questions
What is Boulder's nighttime noise limit for a house?
Does Boulder measure noise differently for construction sites?
Can a business apply for relief from Boulder's decibel limits?
Sources & Official References
Other rules in Boulder
Compare Boulder to another location·View the Colorado noise ordinances overview
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Decibel Limits in Nearby Cities
How other cities in Boulder County handle decibel limits.