Know the Law

Most people — including many students, owners, and even officers — are wrong about what Boulder noise law actually says. The short version: it is stricter, and easier to enforce, than almost anyone believes.

If you can hear it from 100 feet, it’s a violation

Since 2022, amplified sound audible 100 feet beyond the property line at night (11 p.m.–7 a.m.), or 200 feet during the day, is a citable violation — no decibel meter, no complaining neighbor required. An officer can pace the distance and write the ticket (B.R.C. 5-9-6; Ordinance 8531). Every resident present at a house generating amplified noise is legally responsible for it. Police have the choice to drive around neighborhoods and issue tickets.

The decibel limits are health standards

Boulder’s residential limits — 55 dB(A) daytime, 50 dB(A) night (B.R.C. 5-9-3) — descend from the U.S. EPA’s health-based exposure levels and match World Health Organization thresholds. Colorado state law is stricter still: its nighttime limit begins at 7 p.m. (C.R.S. 25-12-103). More on the health page.

Repeat complaints reach the rental license

Under Boulder’s chronic-nuisance ordinance (B.R.C. ch. 10-2.5, 2024), a single-family rental with five or more documented nuisance violations in a year (counted Aug. 1–Jul. 31; no citation is required, and police-documented warnings are evidence of violations) can be designated a chronic nuisance property — triggering a mandatory abatement plan and rental-license consequences up to revocation.

Residents can sue — and reach the owner

Colorado’s Noise Abatement Act lets any resident ask a district court to shut down a noise nuisance and enjoin not just the people making the noise but the owner, lessee, or agent of the property from permitting it (C.R.S. 25-12-104; see Hobbs v. City of Salida, 2025 CO 50).

If you’re hosting a party

We are not against parties. We are against your speakers in our bedrooms. Keep amplified sound indoors, reasonably loud, keep doors and windows shut, wind it down by 11, and nobody calls anyone. A noise ticket in Boulder can run up to $2,650 per violation — each day is a separate violation — and it follows every resident of the house, not just the person at the aux cord.