How Longmont Handles Noise Ordinances: A Practical Guide

Longmont maintains 106 local ordinances across all categories, and 9 of those deal specifically with noise ordinances. Here is a breakdown of what the city actually requires, what is prohibited, and where Longmont falls on the strict-to-permissive spectrum compared to other cities.

Quiet Hours

Longmont's quiet hours run from 10:00 p.m. to 7:00 a.m. under LMC § 10.20.100 and § 10.20.110, when nighttime sound limits apply and many residential activities become prima facie unreasonable noise if audible 25 feet from the source or inside a neighbor's home.

Key details: Code Section: LMC § 10.20.100 & § 10.20.110. Quiet Hours: 10:00 p.m. - 7:00 a.m.. Residential Night Limit: 50 dB(A) at 25 ft. Residential Day Limit: 55 dB(A) at 25 ft. Audibility Trigger: Audible 25 ft from source or inside neighbor's home.

General penalty under Longmont Municipal Court rules: up to $999.00 fine, up to 180 days imprisonment, or both per LMC § 10.20.100 / § 10.20.110 violation.

Barking Dogs

Longmont treats persistent animal noise as a public nuisance under LMC § 7.04.130. An owner who allows a pet to habitually bark, howl, yelp, or otherwise disturb a neighborhood faces enforcement by Longmont Police Animal Control.

Key details: Code Section: LMC § 7.04.130. Standard: Habitual barking that significantly disrupts neighborhood peace. Animal Control Phone: (303) 651-8500. Citation Evidence: Prior warning + 2 households OR video/audio + 1 witness. Mediation Option: (303) 651-8444.

General Longmont Municipal Code penalty: up to $999.00 fine and/or up to 180 days imprisonment. Reports go to Animal Control at (303) 651-8500 or PSpoliceanimalcontrolunit@longmontcolorado.gov.

Amplified Music & Events

Under LMC § 10.20.100(A), amplified sound is prima facie unreasonable noise at any time of day if it is audible 25 feet from the source or inside a private residence the responsible person has no right to occupy. Permitted special events may produce up to 80 dB at the permit perimeter.

Key details: Code Section: LMC § 10.20.100(A). Trigger: Amplified sound audible 25 ft from source — any hour. Special Event Cap: 80 dB at permit perimeter (Ch. 13.37 permit). Definition Reference: LMC § 13.37.020. Permitted Exception: City-approved parades, fireworks, sports, musical productions.

General penalty: up to $999.00 fine and/or up to 180 days imprisonment in Longmont Municipal Court.

Industrial Noise

LMC § 10.20.110 caps noise at 75 dB(A) in industrial zones day or night, measured at least 25 feet from the source. Industrial operations including railroad rights-of-way must keep noise below this ceiling regardless of time of day.

Key details: Code Section: LMC § 10.20.110(A)-(F). Industrial Cap (day & night): 75 dB(A) at 25 ft. Most-Restrictive-Zone Rule: LMC § 10.20.110(E). Refuse/Compactor Hours: No collection 7:00 p.m. - 7:00 a.m. within 500 ft of residential. Truck/Rail Loading Curfew: 10:00 p.m. - 7:00 a.m. within 250 ft of residential lot.

General municipal penalty: up to $999 fine and/or 180 days jail per violation. Temporary hardship permits (max 90 days) may be sought from the city manager.

Construction Hours

Under LMC § 10.20.110(D)(4), construction activity in a residential area or within 500 feet of a school is prohibited between 7:00 p.m. and 7:00 a.m. Monday through Saturday and before 9:00 a.m. on Sundays, unless temporarily approved by the economic development director.

Key details: Code Section: LMC § 10.20.110(D)(4). Weekday/Saturday Allowed: 7:00 a.m. - 7:00 p.m.. Sunday Start: 9:00 a.m.. Sunday/Night Limit Zone: Residential areas + within 500 ft of a school. Daytime dB Cap (residential): 55 dB(A) at 25 ft.

General municipal penalty: up to $999 fine and/or up to 180 days imprisonment under Longmont Municipal Court rules.

Leaf Blower Rules

Longmont does not ban leaf blowers, but LMC § 10.20.110(D)(3) restricts homeowner power equipment — including leaf blowers — to the hours of 7:00 a.m. to 10:00 p.m. and requires equipment mufflers to be in good working condition.

Key details: Code Section: LMC § 10.20.110(D)(3). Allowed Hours: 7:00 a.m. - 10:00 p.m.. Equipment Covered: Mowers, leaf blowers, garden tools, edgers, power saws, riding tractors. Daytime dB Cap (residential): 55 dB(A) at 25 ft. Muffler Requirement: Must be in good working condition.

General Longmont Municipal Code penalty: up to $999.00 and/or up to 180 days imprisonment.

Longmont is more permissive than most cities when it comes to leaf blower rules. That said, there are still limits.

Aircraft Noise

Longmont does not separately regulate aircraft overflight noise. Aircraft operations are pre-empted by federal law administered by the Federal Aviation Administration (FAA), so the city's noise ordinance (LMC § 10.20.100 / § 10.20.110) cannot be applied to in-flight aircraft.

Key details: Local Code: None — not separately regulated. Federal Authority: FAA under 49 U.S.C. § 40103. Local Airport: Vance Brand Municipal Airport (KLMO). Pre-emption Basis: Federal exclusive control of navigable airspace. Where to Complain: FAA / Vance Brand Airport administration.

Not applicable — no local code section. Federal enforcement under 14 CFR Part 91 and FAA noise certification standards.

If you are coming from a city with tighter rules, you will find Longmont gives residents more flexibility on aircraft noise.

Decibel Limits

LMC § 10.20.110 sets dB(A) ceilings measured at least 25 feet from the source: residential 50 night / 55 day, commercial 55 night / 65 day, industrial 75 day and night. Mixed-use dwellings on a non-residential lot are treated as commercial.

Key details: Code Section: LMC § 10.20.110 Tables A & B. Residential: 50 dB(A) night / 55 dB(A) day. Commercial: 55 dB(A) night / 65 dB(A) day. Industrial: 75 dB(A) day & night. Measurement Distance: At least 25 ft from source.

General Longmont Municipal Code penalty: up to $999 fine and/or up to 180 days jail per violation.

Outdoor Music

Outdoor amplified music in Longmont is regulated through LMC § 10.20.100(A) (amplified-sound prohibition audible at 25 feet) combined with the LMC Chapter 13.37 'use of public places' permit, which allows up to 80 decibels at the permit perimeter for authorized special events.

Key details: Code Section: LMC § 10.20.100(A); permit exception via Ch. 13.37. Default Limit: Amplified sound not audible 25 ft from source. Permitted Event Cap: 80 dB at permit perimeter. Permit Type: Use of public places permit (LMC Ch. 13.37). Other Exempt Activities: City-approved parades, fireworks, sports, musical productions.

General municipal penalty: up to $999.00 and/or up to 180 days imprisonment per LMC general-penalty rules.

The Bottom Line

Compared to many U.S. cities, Longmont gives residents more room on noise ordinances. 2 of the 9 rules here are rated permissive. But permissive does not mean unregulated. There are still requirements, and the city does enforce them when violations are reported.

These rules come from Longmont's publicly available municipal code. For complete penalty schedules, exemption details, and answers to common questions, see the individual ordinance pages throughout this guide.