O'Fallon, MO Noise Ordinances: Quiet Hours (2026)
Quiet hours in O'Fallon, MO, also called the noise ordinance, nighttime noise rules, or residential quiet time, define the hours during which excessive noise is prohibited.
Key Facts
- Quiet hours
- 10:30 p.m. to 7:00 a.m.
- Residential nighttime limit
- 50 dB (55 dB daytime)
- Measurement point
- Front building line of receiving property
- Also curbed overnight
- Prolonged yelling or shouting outdoors
- Maximum penalty
- $500 fine per day of violation
- Governing section
- O'Fallon Code § 215-237(L)
Summary
O'Fallon Code § 215-237(L) sets a lower nighttime noise ceiling for residential areas: 55 dB from 7:00 a.m. to 10:30 p.m., dropping to 50 dB from 10:30 p.m. to 7:00 a.m. The same clock governs the ordinance's ban on prolonged yelling or shouting on public streets under Subsection (G)(3). Measurements are taken at the front building line of the property receiving the sound, and a violation can draw a fine of up to $500.00.
L. In addition to the subjective standards established above, it shall be presumed that the allowable noise level limits have been violated whenever any noise or sound is projected from one property in the City onto another if such sound, measured at the front building line on the property receiving the sound, exceeds the following decibel standards at a location appropriate to determine the level of disturbance. 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
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) states that it shall be presumed the allowable noise level limits have been violated whenever any noise or sound is projected from one property in the City onto another if it exceeds the code's objective decibel table, measured at the front building line on the property receiving the sound. ), a five-decibel tightening once the evening curfew hour hits. Commercial districts run 65 dB by day and 60 dB overnight; industrial districts run 70 dB by day and 65 dB overnight. , as an example of unlawful noise even apart from the decibel table.
Measurements must be taken with an ANSI-standard Type II or better sound level meter on the A-weighted, slow-response scale, generally averaged over a fifteen-minute period, per Subsection (K). Multi-family buildings apply the same residential limits between units, measured inside the receiving unit with windows closed. Enforcement follows Subsection (S): written notice, a hearing no sooner than seven days out before the City Administrator or a designate, and, if the violation is upheld, referral to the Police Department and City Prosecutor for a summons in O'Fallon Municipal Court.
Violations & Fines
Exceeding the nighttime residential ceiling of 50 dB after 10:30 p.m., or prolonged street yelling in that same window under § 215-237(G)(3), is punished under Subsection (S)(5): a fine of up to $500.00, with each day of a continuing violation charged separately. The City Administrator or designate must first issue written notice and hold a hearing at least seven days later before referring an unresolved case to the Police Department and Municipal Court.
Frequently Asked Questions
What is O'Fallon's nighttime noise limit for residential neighborhoods?
Does the noise curfew cover more than mechanical or amplified sound?
What happens if a resident is cited for violating the noise curfew?
Sources & Official References
Other rules in O'Fallon
How O'Fallon compares: Cities with the Strictest Noise Ordinances·Compare O'Fallon to another location·View the Missouri noise ordinances overview
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