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Dark Sky Laws by State: US Outdoor Lighting Rules

Published September 23, 2026, updated October 29, 2026

By Peter Benes and Adrienne Kmetz, editors. Updated October 29, 2026.

Only two states, Arizona and New Mexico, have a statute that regulates outdoor lighting broadly across the state. Another 21 states have limited laws that reach only state-funded or public fixtures, a narrow topic such as sea turtles, observatory zones or wind farms, or enabling powers for towns. The other 27 states plus Washington, D.C. have no enacted statewide lighting statute, so cities and counties do the work, as the National Conference of State Legislatures notes. Every row below was re-checked against the statute or bill text on October 29, 2026. You will find a full table for the 50 states and D.C., a shorter one for Canada, the bills moving through legislatures now, and a plain explanation of what these laws require.

Why outdoor lighting got legislated

Outdoor lighting law grew out of four pressures that built up over the last several decades. The earliest was astronomy: observatories at Kitt Peak, Mount Lemmon, and Lowell Observatory pushed Flagstaff, Arizona to pass a searchlight ordinance in 1958 , decades before any state acted, and that same pressure produced Arizona's 1986 statewide statute. Wildlife protection followed: Florida's Section 161.163 sends beachfront lighting guidance to local governments to protect nesting sea turtles, and Illinois's Bird-Safe State Buildings section cuts night lighting on new state buildings to reduce bird collisions. Energy and cost concerns show up in many state-facility statutes, such as Maryland's and Minnesota's , which pay for outdoor lighting only if it is shielded and no brighter than needed. Most recently, glare and light trespass, one neighbor's light spilling into another's bedroom window, has driven municipal nuisance-lighting by-laws, including Calgary's Community Standards Bylaw and Mississauga's Nuisance Lighting By-law .

Safety is the counterweight in every one of these debates. Nobody is arguing for unlit streets, only for light that is shielded and aimed down instead of spilled sideways and up. That distinction, glare versus usable light, is the core idea behind every ordinance on this page, and it is explained in more detail in our guide to dark-sky-friendly outdoor lighting.

Dark sky laws in all 50 states and Washington, D.C.

"Statewide law" means a statute that regulates outdoor lighting broadly, beyond only state-funded or public fixtures. "Limited law" means a statute exists but covers only state-funded or public fixtures, a narrow category (sea turtles, observatory zones, wind farms) or enabling powers. "No statewide law" means no enacted statute; any rules come from cities and counties. Each state name links to its own page in the dark sky laws hub with the full statute list, municipal codes and sources.

Dark Sky Laws by State: Comparison Table

State Status Main law What it covers
Alabama No statewide law None Nothing statewide; cities and counties set any rules
Alaska No statewide law None; see Anchorage code Nothing statewide; Anchorage code curbs glare and trespass at parking lots
Arizona Statewide law A.R.S. §§ 49-1101 to 49-1104 (1986) Shielded outdoor fixtures statewide; older fixtures off midnight to sunrise; no new mercury vapor
Arkansas Limited law Ark. Code §§ 8-14-101 to 8-14-107 (2005) Public money cannot buy unshielded fixtures; local rules can override
California No statewide law None; see Title 24, Part 6 § 130.2 No dark-sky statute; Title 24 energy code sets outdoor lighting controls and BUG limits
Colorado Limited law C.R.S. § 24-82-902 (2001) Full cutoff fixtures on state-funded lighting; 2022 Dark Sky grants
Connecticut Limited law Conn. Gen. Stat. § 4b-16 (2006) State building grounds and state and municipal-funded roads
Delaware Limited law Del. Code tit. 7, § 7102A (SB 127) (2005) Cutoff luminaires on state-funded outdoor lighting
District of Columbia No statewide law D.C. Code § 8-1776.02 (2010) A lighting study only; no limits
Florida Limited law Fla. Stat. § 161.163; Fla. Admin. Code r. 62B-55 (1986) Sea turtle beachfront model ordinance, enforced by about 90 local ordinances
Georgia No statewide law None Nothing statewide; sea turtle rules are local (Glynn County, Jekyll Island)
Hawaii Limited law Haw. Rev. Stat. § 201-8.5 (2012) Shielded, 4,000 K or cooler state-agency fixtures; mercury vapor ban
Idaho No statewide law None Nothing statewide; Ketchum has its own code
Illinois Limited law 20 ILCS 405/405-317 (2021) Bird-safe lighting on new state buildings
Indiana No statewide law None Only glare, airport and wind turbine rules; Beverly Shores has an ordinance
Iowa No statewide law None Only highway display and traffic-light rules
Kansas No statewide law None Only highway sign and wind turbine rules
Kentucky No statewide law None Only highway advertising and flashing-light rules
Louisiana No statewide law None Nothing statewide; parish and city codes only
Maine Limited law 5 M.R.S. § 481 (LD 1934) (2026) Public outdoor lighting: 3,000 K cap, shielding, night curfew; towns may go stricter
Maryland Limited law State Fin. & Proc. § 14-412; HB 452 (2011, 2025) State-funded lighting; 2025 law adds parks, trails and a 3,000 K limit
Massachusetts No statewide law None; see source Dark Skies bill S.3162 passed the Senate 39 to 0 on July 1, 2026; not law yet
Michigan Limited law MCL §§ 324.75101 to 324.75104 (Part 751) (1995) Lighting rules inside eight named state Dark Sky Preserves
Minnesota Limited law Minn. Stat. § 16B.328 (2007) Cutoff luminaires on state-funded lighting
Mississippi No statewide law None Nothing statewide; cities and counties only
Missouri No statewide law None Only highway sign lighting rules
Montana No statewide law None; see source Nothing statewide; Missoula, Whitefish and others have codes
Nebraska No statewide law None Nothing statewide; cities and counties only
Nevada Limited law NRS 407A.570 (SB 52) (2021) Voluntary Dark Sky designation program; no fixture rules
New Hampshire Limited law RSA 9-E (2009) Shielded fixtures on state-funded lighting; encourages local ordinances
New Jersey No statewide law None; see source Bill S1635 pending; 1993 study commission only
New Mexico Statewide law Night Sky Protection Act, NMSA §§ 74-12-1 to 74-12-11 (1999) Shielded fixtures statewide, 11 p.m. recreation curfew, mercury vapor ban
New York Limited law Public Buildings Law § 143 (2014) Shielded lights on state agency projects
North Carolina No statewide law None; see source Sea Turtle Protection Act (H1053, 2023) stalled in committee
North Dakota No statewide law None; see source Dark Sky Week resolution SCR 4004 failed in 2025
Ohio No statewide law None; see source Nothing statewide; local codes such as Moreland Hills
Oklahoma No statewide law None Only vehicle lamp rules
Oregon Limited law ORS 455.573 (2009) Shielded fixtures on public buildings
Pennsylvania No statewide law None; see source HB 1803 (2023) cleared committee but was not enacted
Rhode Island Limited law R.I. Gen. Laws §§ 42-136-1 to 42-136-6 (2002) Uplight limit on state-installed fixtures over 3,200 lumens
South Carolina No statewide law None; see source Sea Turtle Protection Act bills stalled in Senate committee since 2010
South Dakota No statewide law None Nothing statewide; cities and counties only
Tennessee No statewide law None; see source Nothing statewide; Nashville has Dark Sky Ordinance BL2020-535 (2021)
Texas Limited law Health & Safety Code ch. 425; Local Gov't Code § 240.032 and ch. 229 (1999, 2011) State-funded cutoff lights; counties and towns near McDonald Observatory must regulate
Utah No statewide law None; see source Only non-binding resolutions (2003, 2018); Moab, Hideout and Park City have codes
Vermont Limited law 10 V.S.A. § 591 (2005) Advisory board and voluntary guidelines
Virginia Limited law Va. Code §§ 2.2-1111 and 15.2-920 (1980, 1997) Shielded fixtures at state agencies; localities may regulate near observatories
Washington Limited law Laws of 2023, ch. 344 (ESHB 1173) (2023) Wind farm aircraft-detection lighting, deadline 2028
West Virginia No statewide law None; see source HB 2995 (1999) never passed; reached committee referral only
Wisconsin No statewide law None; see source Nothing statewide; Madison and Town of Amnicon have ordinances
Wyoming Limited law Wyo. Stat. §§ 37-16-201 and 37-16-202 (2003) Utilities must offer a dark-sky-friendly lighting tariff

The states that led the way

Arizona passed the first statewide outdoor lighting law in 1986 , requiring shielded fixtures and later switching older ones off from midnight to sunrise, building on Flagstaff's 1958 searchlight ordinance and the observatory movement around Kitt Peak. Flagstaff itself became the world's first International Dark Sky Place in 2001 . Michigan's Dark Sky Preserve law followed in 1995 (Part 751), though it governs lighting only inside eight named state-owned preserves. New Mexico's Night Sky Protection Act of 1999 became the second broad statewide law: fixtures installed after January 1, 2000 must be shielded, new mercury vapor fixtures are barred, and outdoor recreation fields must go dark after 11 p.m. except for a game in progress. A first violation draws a warning, then $25 per fixture.

Most other states chose narrower tools. Arkansas's Shielded Outdoor Lighting Act of 2005 bars public money from paying for unshielded fixtures, and Delaware's SB 127, approved July 20, 2005 , requires cutoff luminaires on state-funded lighting over 1,800 lumens. Both stop short of private property. Maine's 2026 Responsible Outdoor Lighting law (LD 1934) is the newest and most detailed: it took effect in January 2026 and applies to public outdoor lighting installed or replaced from October 1, 2026. It caps color at 3,000 kelvin, requires full shielding above 1,000 lumens, limits light levels to 125 percent of ANSI/IES guidance and turns nonessential lighting off at night. It does not mandate anything on private property; it lets towns adopt stricter rules of their own. Massachusetts could be next: the Senate passed its Dark Skies bill, S.3145 (reprinted as S.3162) , 39 to 0 on July 1, 2026, but as of August 2026 the House had not agreed on a final text, so nothing is law yet.

Recently passed and pending bills (2025 to 2026)

Canadian provinces and territories

No Canadian province or territory has a dedicated outdoor-lighting or dark-sky statute that we could find. Protection comes from municipal by-laws, park policy, and national and provincial parks that carry a Royal Astronomical Society of Canada (RASC) Dark-Sky Preserve designation. Manitoba is the only province with a formal park policy program.

Province or territory Status Key rule or by-law Notes
Alberta No provincial law Calgary Bylaw 32M2023, s. 36 (2023) Bans outdoor lights shining into a neighbor's living or sleeping area. Bon Accord Bylaw 2015-07 requires shielded fixtures.
British Columbia No provincial law Saanich council policy (1992); Comox Valley DarkSky Policy (2007) Local shielding and curfew policies; a 2015 Vancouver motion led to no by-law.
Manitoba Provincial park policy Manitoba Parks Dark-Sky Preserve program (2022) Not a statute. Spruce Woods Provincial Park became a RASC preserve on September 4, 2022.
New Brunswick No provincial law No lighting by-law found Protection by designation: Mount Carleton, Kouchibouguac and Fundy are RASC preserves .
Newfoundland and Labrador No provincial law No lighting law found Terra Nova National Park became a RASC preserve on March 12, 2018.
Northwest Territories No territorial law No lighting law found Wood Buffalo National Park, shared with Alberta, is a RASC preserve (2013).
Nova Scotia No provincial law Argyle draft Bylaw 43 stalled The draft passed first reading in 2025 only. Kejimkujik National Park is a RASC preserve .
Nunavut No territorial law No lighting law found No Nunavut site appears on the RASC list .
Ontario No provincial law Windsor By-law 146-2025 ; Huntsville (2016); Muskoka Lakes Full cut-off fixtures required locally. Mississauga By-law 262-12 (2012) bans glaring floodlights.
Prince Edward Island No provincial law No lighting law found No Island site appears on the RASC list .
Quebec No provincial law MRC du Granit by-law 2020-11 and related by-laws Around Mont-Megantic: 2,200 K color cap, under 1% uplight, lights off or dimmed after 10 or 11 p.m.
Saskatchewan No provincial law No lighting law found A 2007 Law Reform Commission paper suggested by-laws; Cypress Hills and Grasslands are protected sites .
Yukon No territorial law No lighting law found Proposals for Kluane and Chadburn Lake (2017); no designated site.

Quebec's rules are the most detailed in the country. Three local authorities around the Mont-Megantic International Dark Sky Reserve , Sherbrooke, the MRC du Haut-Saint-Francois and the MRC du Granit, cap color at 2,200 kelvin for most uses, limit upward light to under 1 percent (2.5 percent for low fixtures) and require lights off or dimmed after 10 or 11 p.m.

Municipal ordinances: where most of the real protection lives

Because 27 US states, D.C. and every Canadian province lack a broad statewide law, cities and counties do most of the regulating. In Arizona, Flagstaff's lighting code traces to a 1958 searchlight restriction, while the joint Tucson and Pima County outdoor lighting code protects the observatories on Kitt Peak and Mount Lemmon. In Colorado, Westcliffe and Silver Cliff became the state's first International Dark Sky Community in 2015. In Tennessee, Nashville's Dark Sky Ordinance (BL2020-535, passed April 6, 2021) caps color temperature at 3,000 kelvin and covers private streetlights and new commercial and multifamily buildings. In Ontario, Huntsville's by-law required full cutoff, downward-shielded fixtures on new construction from January 2016 and gave existing owners until January 2026 to upgrade. Florida works as a hybrid: the state publishes a model lighting ordinance for sea turtle protection under Rule 62B-55, and it takes legal effect only where a county or city adopts it. The Florida Fish and Wildlife Conservation Commission lists roughly 90 such ordinances across 26 counties, including Volusia County's and Sarasota's .

If your town has no ordinance at all, New Jersey's model lighting ordinance template and the joint IDA-IES Model Lighting Ordinance are the two most useful starting drafts for a town council to adapt.

What a good outdoor lighting ordinance actually requires

Whether it is a 1986 state statute or a 2025 by-law, the ordinances that hold up converge on a handful of rules, closely tracking DarkSky International's five principles for responsible outdoor lighting : light should have a clear purpose, be directed only where needed, be no brighter than necessary, be controlled with timers or motion sensors, and use warmer colors. In statute language that becomes four concrete requirements. Shielding: fixtures must be "fully shielded" or "full cutoff," meaning no light escapes above the horizontal plane of the fixture, the core requirement in Arizona's and New Mexico's laws and in Maine's rule for public lighting above 1,000 lumens. Color temperature: newer rules such as Maine's and Maryland's cap fixtures at 3,000 kelvin, and Quebec's Mont-Megantic zone goes further at 2,200 kelvin, because bluer light scatters more in the atmosphere and washes out more stars. Brightness limits: many state-funded lighting laws, including Maryland's , Minnesota's and Delaware's , apply their shielding rule to fixtures over 1,800 lumens. Curfews: New Mexico bars lighting outdoor recreation fields after 11 p.m., Maine turns nonessential public lighting off at night, and Quebec's regional rules set 10 or 11 p.m. cutoffs.

Homeowners who want to meet these standards on their own property, whether or not their town requires it, can find fixture-by-fixture guidance in our dark-sky-friendly outdoor lighting guide.

How to push for a lighting ordinance in your town

Every ordinance on this page started with a resident or a small group raising the issue with a town council or county board, usually with three ingredients: a specific complaint (glare from a new development, a sports field lit past bedtime, a stargazing spot losing its view), a model to point to (the IDA-IES Model Lighting Ordinance or a neighboring town's by-law, such as Huntsville's ), and a council member willing to sponsor a vote. New Hampshire's RSA 9-E:3 explicitly encourages towns to take that path without requiring it. DarkSky International's International Dark Sky Places program certifies parks, communities, and preserves that adopt qualifying lighting rules, giving a town a concrete goal, as it did for Bon Accord, Alberta , the first International Dark Sky Community in Canada. Once a rule passes, the certified places it protects show up in our dark sky places directory, and the celestial events worth protecting a dark view for are on our events calendar.

Quick answers

Which US states have dark sky laws? Only Arizona (1986) and New Mexico (1999) have statutes that regulate outdoor lighting broadly. Twenty-one more states have limited laws covering state-funded or public fixtures, a narrow topic like sea turtles, or enabling powers: Arkansas, Colorado, Connecticut, Delaware, Florida, Hawaii, Illinois, Maine, Maryland, Michigan, Minnesota, New Hampshire, Nevada, New York, Oregon, Rhode Island, Texas, Virginia, Vermont, Washington and Wyoming. The remaining 27 states and Washington, D.C. have no enacted statewide statute .

Is light pollution illegal? Only where a specific law makes it so. In Arizona and New Mexico , unshielded new outdoor fixtures above the statutory wattage or size exemptions break state law; in most other states a neighbor's glaring floodlight is a nuisance matter for local code enforcement or civil court, unless your city has its own by-law like Mississauga's .

What is a full cutoff fixture requirement? It means a fixture is built and aimed so no light escapes above its horizontal plane, eliminating direct uplight into the sky. It is the central mechanic of Arizona's , New Mexico's and Maine's rules and most municipal codes on this page.

Do any Canadian provinces regulate outdoor lighting? No province has a dark-sky statute. Manitoba runs a park-based Dark-Sky Preserve program, and the strictest rules are local, such as the regional by-laws around Quebec's Mont-Megantic reserve and Ontario towns like Huntsville and Windsor .

Can my neighbor's light be a legal nuisance? Where a light-trespass by-law exists, such as Calgary's , yes: a light shining directly into your living or sleeping area can be reported and fined. Elsewhere it usually falls under general nuisance law, which varies by state, so check with your local code enforcement office first.

Which state passed the first dark-sky law? Arizona, in 1986 , remains the oldest statewide outdoor lighting law, though Flagstaff's 1958 municipal searchlight restriction predates it. To see how light pollution affects what you can actually see at night, read our guide to stargazing for beginners.

Sources

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