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 — drop the volume at 7 p.m. when the state nighttime limit kicks in (C.R.S. 25-12-103), take it fully indoors by 11 when the city’s 100-foot rule starts — 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.