Portland, ME Noise Ordinances: Decibel Limits (2026)
Key Facts
- Quietest zone
- B-1: 55 dBA day and night
- Loudest zone
- I-H: 75 dBA day, 55 dBA night
- Daytime/evening window
- 7 a.m.–9 p.m.
- Night window
- 9 p.m.–7 a.m.
- Governing section
- Land Use Code § 6.8.6(B), Table 6-H
- Construction exemption
- 7 a.m.–9 p.m., Sec. 6.8.6(F)(1)
Summary
Portland's Land Use Code sets numeric decibel ceilings by zoning district and time of day. Table 6-H fixes daytime/evening (7 a.m.–9 p.m.) and nighttime (9 p.m.–7 a.m.) sound limits ranging from 55 dBA in the B-1 zone up to 75 dBA in the industrial I-H zone.
A. No use shall be operated so as to generate recurring noises that are unreasonably loud, cause injury, or create a nuisance to any person of ordinary sensitivities. B. The maximum permissible sound level of any continuous, regular, or frequent source of sound produced by an activity shall be as shown in Table 6-H. ... Zone (7 a.m.-9 p.m.) (9 p.m.-7 a.m.): B-1 55 dBA 55 dBA; B-4 65 dBA 60 dBA; I-H 75 dBA 55 dBA.
Official source re-checked September 7, 2026: the cited page had not changed since it was quoted.
Full Breakdown
' The table sets a two-tier limit for every zone: B-1 is capped at 55 dBA both day and night; B-2/B-2b and B-3 allow 60 dBA daytime with a 55 dBA nighttime ceiling; A-B allows 60 dBA both periods; B-4 allows 65 dBA daytime and 60 dBA at night; the industrial I-M/I-Mb zone allows 70 dBA daytime; and I-H, the loosest zone, allows 75 dBA daytime and 55 dBA at night. Measurement location depends on zone: for the I-L/I-Lb, I-M/I-Mb, and I-H industrial zones, sound is measured at or within the boundary of the nearest residential zone; for B-1 through B-6, TOD, I-B, O, and A-B zones, it's measured at the lot boundary, using a sound level meter meeting ANSI frequency-weighting standards.
, safety and emergency devices, traffic on public roads, aircraft and railroad noise, refuse collection, emergency utility repair at any hour, and permitted or licensed recreational events such as concerts, parades, and fireworks.
Violations & Fines
A use that exceeds its zone's Table 6-H limit is enforceable as a Land Use Code violation under Section 1.5.1's Building Authority and Code Enforcement Officer authority, with fines of $100 to $500 per day under Code of Ordinances Section 1-15. Complaints are resolved with an on-site sound-level-meter reading taken at the measurement point Section 6.8.6(C) specifies for the zone: the lot boundary for most zones, or the nearest residential zone boundary for industrial uses.
Frequently Asked Questions
What is the noise limit in Portland, Maine's business zones?
Are there different noise limits for day and night in Portland?
Is construction noise exempt from Portland's noise limits?
Sources & Official References
Other rules in Portland
Compare Portland to another location·View the Maine noise ordinances overview
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