Ontario, CA Noise Ordinances: Decibel Limits (2026)
Key Facts
- Zone I (single-family)
- 65 dBA day, 45 dBA night
- Zone II (multi-family/mobile home)
- 65 dBA day, 50 dBA night
- Zone III (commercial)
- 65 dBA day, 60 dBA night
- Zones IV & V (mixed-use, industrial)
- 70 dBA day and night
- Instantaneous peak cap
- standard plus 20 dBA
- Averaging period
- any 15-minute period
- Enforcing agency
- Police or Code Enforcement Officers
Summary
Ontario divides every parcel into five noise zones and sets numeric dBA ceilings for each: 65 dBA daytime for single-family and multi-family homes, dropping to 45 dBA and 50 dBA at night, 65/60 dBA for commercial property, and a flat 70 dBA day and night for mixed-use residential and manufacturing/industrial zones under Ontario Municipal Code § 5-29.04.
(a) The following exterior noise standards, unless otherwise specifically indicated, shall apply to all properties within a designated noise zone.
Allowable Exterior Noise Level (1) Allowed Equivalent Noise Level, Leq. (2) Noise Zone Type of Land Use 7 a.m. to 10 p.m. 10 p.m. to 7 a.m.
I Single-Family Residential 65 dBA 45 dBA II Multi-Family Residential, 65 dBA 50 dBA Mobile Home Parks III Commercial Property 65 dBA 60 dBA IV Residential Portion of 70 dBA 70 dBA Mixed Use V Manufacturing and 70 dBA 70 dBA Industrial, Other Uses
Official source re-checked September 7, 2026: no newer edition of the code had been published (publisher’s edition: 2026 S-32: Current through Ordinance 3338, passed 7-21-2026).
Full Breakdown
03 assigns every parcel to one of five noise zones based on actual use rather than zoning designation: Zone I is single-family residential, Zone II is multi-family residential and mobile home parks, Zone III is commercial property, Zone IV is the residential portion of mixed-use property, and Zone V covers manufacturing, industrial and all other uses. m. Single-family homes (Zone I) may not exceed 65 dBA by day or 45 dBA at night; multi-family and mobile home parks (Zone II) top out at 65 dBA by day and 50 dBA at night; commercial property (Zone III) runs 65 dBA by day and 60 dBA at night; mixed-use residential (Zone IV) and manufacturing/industrial (Zone V) both carry a flat 70 dBA ceiling around the clock.
04(b) makes it unlawful to cause noise on any other property that exceeds the applicable zone standard for any fifteen-minute period, or that hits an instantaneous peak of the standard plus 20 dBA measured with A-weighted slow response. If the ambient noise already exceeds the printed standard, subsection (c) raises the ceiling to match the ambient level. Residential property within 100 feet of a commercial use borrows the Zone IV standard under subsection (d), and a parcel straddling two zones takes the lower of the two under subsection (e).
05 sets parallel interior limits of 45 dBA daytime and 40 dBA nighttime for Zones I, II and IV. 15 fixes the measurement point at the affected property's yard, patio, deck or balcony.
Violations & Fines
A confirmed violation of §§ 5-29.04 or 5-29.05 is an infraction under § 5-29.17, punishable by the fine schedule in OMC § 1-2.01, with each day of continuing violation charged as a separate offense. Police or Code Enforcement Officers may also issue an administrative citation under the fine schedule in § 1-5.04, and the City can seek an injunction or restraining order abating the noise as a public nuisance.
Frequently Asked Questions
What is the nighttime noise limit for a house in Ontario?
Does the noise limit change if my street is already loud?
Are indoor noise levels regulated separately from outdoor noise in Ontario?
What happens if my neighbor's noise briefly spikes above the limit?
Sources & Official References
Other rules in Ontario
California rules heatmap·Compare Ontario to another location·View the California noise ordinances overview
See something wrong?
Help us keep this page accurate. If you notice an error or outdated information, let us know.
Decibel Limits in Nearby Cities
How other cities in San Bernardino County handle decibel limits.