How Longmont Handles Noise Ordinances: A Practical Guide

Longmont maintains 129 local ordinances across all categories, and 8 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.

Leaf Blower Rules

Homeowners' engine- or motor-powered lawn tools, including leaf blowers, power mowers, edgers and riding tractors, can't exceed Longmont's fixed noise standards outside 7 a.m. to 10 p.m. under Municipal Code § 10.20.100(D)(3); mufflers must stay in good repair, and snow blowers and snowplows are exempt from the hours.

Key details: Allowed hours: 7 a.m.-10 p.m.. Covered equipment: leaf blowers, mowers, edgers, saws, tractors. Residential noise cap: 50 dB(A) night, 55 dB(A) day, at 25 ft. Snow equipment: exempt from the time limit. Hardship permit: up to 90 days, city manager approval.

Chapter 10.20 sets no separate criminal fine for a leaf-blower violation, so the Title 1.12.010 general penalty applies: up to a $500 fine and up to 90 days. Section 10.20.110 additionally deems a violation of § 10.20.100 a public nuisance, letting the city attorney sue to enjoin repeated or ongoing noise from a property.

Aircraft Noise

Pilots using Longmont's Vance Brand Municipal Airport are directed to fly recommended traffic pattern altitudes designed to limit noise over nearby neighborhoods under Longmont Municipal Code § 13.39.040(K). Small aircraft fly at 1,000 feet AGL, larger and turbine aircraft at 1,500 feet, and helicopters, ultralights and gyrocopters at 500 feet, and § 13.39.040(K)(3) directs pilots to follow separately published noise-abatement traffic patterns when possible.

Key details: Small aircraft altitude: 1,000 feet AGL. Larger/turbine aircraft: 1,500 feet AGL. Helicopters/ultralights/gyrocopters: 500 feet AGL. Noise-abatement patterns: published on airport dept webpage (K.3). Airport: Vance Brand Municipal Airport.

A pilot who disregards the traffic-pattern altitudes in § 13.39.040(K)(1) or ignores a posted noise-abatement pattern without an air-traffic-control authorization or a safety justification can be found in violation of chapter 13.39, punishable in municipal court by a fine of up to $500.00 under § 13.39.020(H). The airport manager may also issue a written notice of violation giving ten business days to respond, and can pursue other remedies, including revoking a commercial operator's airport permit, under § 13.39.020(E)-(F).

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

Barking Dogs

Longmont declares an animal a public nuisance if its owner or keeper permits it to habitually bark, howl or make other noise that significantly disrupts the neighborhood's peace under a reasonable-person standard.

Key details: Standard: Habitual, significantly disruptive noise. Test: Reasonable, ordinary-sensibilities neighbor. Legal status: Declared a public nuisance. Max penalty: $500 fine, 90 days jail.

A qualifying animal is declared a public nuisance under § 7.04.210; violating chapter 7.04 is a strict-liability offense under § 7.04.240, punishable by up to a $500 fine, 90 days imprisonment, or both under the Chapter 1.12 general penalty.

Vehicle Noise

Longmont deems motor vehicle noise from a licensed, non-commercial vehicle audible 300 feet away, from its engine, exhaust, or brakes, automatically unreasonable noise.

Key details: Trigger distance: Audible 300 feet away. Covers: Engine, exhaust, brake noise. Applies to: Licensed, non-commercial vehicles. Legal status: Prima facie unreasonable, public nuisance.

Public nuisance; enforceable by city attorney injunction and standard Code violation penalties.

Quiet Hours

Longmont presumes certain noise between 10 p.m. and 7 a.m. unreasonable and unlawful: audible engines, tools, repairs, or loud gatherings within 25 feet of a neighbor trigger a violation without further proof.

Key details: Quiet hours: 10 p.m. to 7 a.m.. Trigger distance: Audible 25 feet from source. Vehicle-noise trigger: Audible 300 feet away. Event exception: 80 dB(A) or less, permitted event.

A listed nighttime noise is a municipal offense on its face; the city attorney can also pursue it as a public nuisance in civil court under § 10.20.110.

Construction Hours

Longmont bans construction activity noise in residential areas or within 500 feet of a school between 7 p.m. and 7 a.m. weekdays and Saturdays, and before 9 a.m. on Sundays, absent an approved exception.

Key details: Quiet hours: 7pm-7am Mon-Sat, before 9am Sun. Coverage area: residential areas or within 500 ft of school. Exception: economic development director approval. Enforcement: public nuisance action, §10.20.110.

Construction noise outside permitted hours near residences or schools is a public nuisance under §10.20.110; the city attorney may sue to enjoin it.

Amplified Music & Outdoor Sound

Longmont treats amplified sound audible 25 feet from its source, or inside a private residence, as unreasonable noise and a public nuisance under its general noise ordinance.

Key details: Trigger distance: Audible 25 feet from source. Legal status: Prima facie unreasonable noise. Enforcement: Public nuisance, injunction available. Event exception: 80 dB(A) at permit perimeter.

Violation is a public nuisance; the city attorney can seek an injunction, and it is enforceable under the general penalty provisions for Code violations.

Decibel Limits

Longmont caps sound measured 25 feet from the source at 50-55 dB(A) in residential zones, 55-65 dB(A) commercial, and 75 dB(A) industrial, with the lower numbers applying overnight.

Key details: Night residential limit: 50 dB(A). Night industrial limit: 75 dB(A). Day residential limit: 55 dB(A). Day industrial limit: 75 dB(A). Measurement point: 25 feet from source.

Exceeding the table is a municipal noise violation, independently enforceable as a public nuisance the city attorney can seek to enjoin under § 10.20.110.

The Bottom Line

Longmont's noise ordinances rules are a mixed bag. Some areas are strict, others are relaxed, and the details matter. The best approach is to check the specific rule that applies to your situation rather than assuming Longmont is broadly strict or permissive.

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.