Montgomery County, MD Noise Ordinances: Decibel Limits (2026)
Key Facts
- Non-residential limit
- 67 dBA daytime / 62 dBA night
- Residential limit
- 65 dBA daytime / 55 dBA night
- Enforcing agency
- Dept. of Environmental Protection
- Violation class
- Class A, $500-$750 civil fine
- Measurement point
- Receiving property where noise is greatest
Summary
Montgomery County caps industrial and commercial noise at 67 dBA daytime and 62 dBA nighttime in non-residential noise areas under County Code Chapter 31B, enforced by the Department of Environmental Protection.
a person must not cause or permit noise levels that exceed the following levels:
Maximum Allowable Noise Levels (dBA) for Receiving Noise Areas
Daytime
Nighttime
Non-residential noise area
67
62
Residential noise area
65
55
(2) A person must not cause or permit the emission of a prominent discrete tone or impulsive noise that exceeds a level, at the location on a receiving property where noise from the source is greatest, that is 5 dBA lower than the level set in paragraph (1) for the applicable noise area and time.
(3) Sound that crosses between residential and non-residential noise areas must not exceed the levels set in paragraph (1) for residential noise areas.
(b) Noise disturbance. A person must not cause or permit noise that creates a noise disturbance.
(c) Examples. The following examples illustrate common noise-producing acts that violate this section if they exceed the noise level standards set in subsection (a) or create a noise disturbance. The examples are illustrative only and do not limit or expand the noise level or noise disturbance standards of this section:
(1) Sounding a horn or other signaling device on any motor vehicle on private property except:
(A) in an emergency; or
(B) as a danger warning signal during daytime hours if the device complies with noise level limits.
(2) Operating a sound-producing device on public streets for commercial advertising or to attract public attention.
(3) Selling anything by outcry.
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-90: Montgomery County Code contains legislation effective through May 7, 2026 | Zoning Updated Effective: April 13, 2026 | COMCOR Regulations effective as of July 1, 2026).
Full Breakdown
Montgomery County Code § 31B-5(a) sets maximum noise levels of 67 dBA daytime and 62 dBA nighttime for non-residential noise areas, measured at the receiving property line; residential areas are capped lower at 65/55 dBA. Sound crossing from a non-residential source into a residential area must meet the stricter residential limit, and a prominent discrete tone or impulsive noise cannot exceed the applicable limit by more than 5 dBA. The Department of Environmental Protection enforces the chapter; a violation is a Class A violation carrying a $500 civil fine for a first offense and $750 for a repeat offense under § 1-19.
Violations & Fines
Exceeding 67/62 dBA (non-residential) or 65/55 dBA (residential) is a Class A violation: up to $500 civil fine (first offense), $750 (repeat), or a $1,000 criminal fine and up to 6 months jail.
Frequently Asked Questions
What's the maximum industrial noise level in Montgomery County?
What happens if a business exceeds the noise limit?
Sources & Official References
Other rules in Montgomery County
Compare Montgomery County to another location·View the Maryland noise ordinances overview
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