Douglas County, CO Noise Ordinances: Quiet Hours (2026)
Quiet hours in Douglas County, CO, also called the noise ordinance, nighttime noise rules, or residential quiet time, define the hours during which excessive noise is prohibited.
Key Facts
- Daytime limit
- 55 dB(A), 7 a.m.-7 p.m.
- Nighttime limit
- 50 dB(A), 7 p.m.-7 a.m.
- Applies to
- Unincorporated Douglas County
- Authority
- Zoning Resolution Section 17A
- Measured
- 25+ feet from lot line
Summary
In unincorporated Douglas County (including Highlands Ranch), residential and agricultural zones may not exceed 55 dB(A) from 7:00 a.m. to 7:00 p.m., dropping to 50 dB(A) overnight from 7:00 p.m. to 7:00 a.m. Castle Rock and Parker set their own limits.
The following are the maximum permissible noise levels that may be emitted from lots or parcels within the following zone districts: A-1/LRR/RR/ER/SR/MF/MH -- 55 dB(A) [7:00 a.m. to next 7:00 p.m.]; 50 dB(A) [7:00 p.m. to next 7:00 a.m.].
Full Breakdown
Section 17A of the Douglas County Zoning Resolution sets maximum permissible noise levels for all land in the unincorporated county, which covers Highlands Ranch, Roxborough and other CDPs. In the A-1, LRR, RR, ER, SR, MF and MH zone districts the cap is 55 dB(A) daytime (7 a.m.-7 p.m.) and 50 dB(A) nighttime. Sound is measured 25 feet or more from the lot line of the noise source. Incorporated towns (Castle Rock, Parker, Lone Tree) enforce their own municipal noise codes rather than the county resolution.
Violations & Fines
Enforced by Douglas County as a Zoning Resolution violation; abatement and penalties follow county code-enforcement and C.R.S. Article 12 noise provisions.
Frequently Asked Questions
Do these limits apply in Highlands Ranch?
Do the county limits apply inside Castle Rock?
Sources & Official References
Other rules in Douglas County
How Douglas County compares: Cities with the Strictest Noise Ordinances·Compare Douglas County to another location·View the Colorado noise ordinances overview
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