O'Fallon, MO Noise Ordinances: Decibel Limits (2026)
Key Facts
- Residential daytime limit
- 55 dB (7 a.m.-10:30 p.m.)
- Residential nighttime limit
- 50 dB (10:30 p.m.-7 a.m.)
- Commercial limit
- 65 dB day / 60 dB night
- Industrial limit
- 70 dB day / 65 dB night
- Measurement point
- Front building line, receiving property
- Meter standard
- ANSI S1.4 Type II, A-weighted, slow
Summary
O'Fallon sets objective decibel ceilings by zoning district and time of day: 55/50 dB in residential zones, 65/60 dB in commercial zones, and 70/65 dB in industrial zones, measured at the receiving property's front building line under City Code § 215.237(L).
Objective Noise Standards—Allowable Levels In residentially zoned districts: 7:00 A.M. to 10:30 P.M. 55 dB 10:30 P.M. to 7:00 A.M. 50 dB In commercially zoned districts: 7:00 A.M. to Midnight 65 dB Midnight to 7:00 A.M. 60 dB In industrially zoned districts: 7:00 A.M. to Midnight 70 dB Midnight to 7:00 A.M. 65 dB
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: rev 4860992; v58 updated 2026-05-14; through 05-14-2026).
Full Breakdown
237(L) presumes a noise violation whenever sound projected from one property onto another, measured at the front building line of the receiving property, exceeds the chapter's numeric table. m. to midnight and 60 dB overnight. to midnight and 65 dB overnight. Multi-family buildings apply the same limits between units, measured inside the receiving unit with windows closed. 4 sound level meter on the A-weighted, slow-response scale, generally averaged (Leq) over a 15-minute period, and the meter must be positioned 3 to 10 feet above ground with a line of sight to the source when possible.
, emergency vehicles, permitted parades and demonstrations under two hours, City-sponsored public affairs, aircraft, holiday noisemakers and fireworks, and trains operated properly. Annexed property with non-residential zoning gets twelve months to come into compliance, and new residential or lodging development proposed within 1,000 feet of an existing commercial or industrial zone must demonstrate 35 dBA of sound attenuation from outside to inside the structure.
Violations & Fines
A measured or presumed violation triggers written notice from the City Administrator under § 215.237(Q), followed by a hearing on request (§ 215.237(S)). Sustained violations can be referred to the Police Department for a complaint and summons to O'Fallon Municipal Court, carrying the § 100.010 general penalty of up to $500.00 and/or three months imprisonment.
Frequently Asked Questions
What is O'Fallon's nighttime noise limit for a residential neighborhood?
How does O'Fallon measure noise for enforcement?
Are commercial and industrial areas allowed louder noise than residential areas in O'Fallon?
Sources & Official References
Other rules in O'Fallon
Compare O'Fallon to another location·View the Missouri noise ordinances overview
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