Outdoor Lighting in Thornton, CO (2026)
2 verified outdoor lighting rules for Thornton, Colorado, sourced directly from the municipal code and official government pages.
Verified from official government sources
Dark Sky Rules
For non-residential off-street parking used after dark in the South Thornton Urban Renewal Authority area, City Code Section 10-260(d) requires shielded, indirect or diffused light fixtures no higher than 35 feet, aimed so light is not directed at residential uses, with minimum intensity of one foot-candle average and four-tenths foot-candle at any point.
South Thornton Lots Need Shielded Parking Lights
Some RestrictionsThornton City Code § 10-260(d)
(d)Off-street lighting. Off-street parking for non-residential uses that offers service after dark shall be lighted beginning one-half hour after sunset and continuing throughout the hours of use. If only a portion of the parking area is offered for use after dark, only that part shall be lighted. The lighting of the off-street parking area shall meet the following minimum requirements:(1)The i...
Light Trespass & Shielding
Thornton requires exterior and interior lighting in every zoning district to be designed and installed so direct rays stay confined to the site where the fixture sits, protecting adjacent residential properties from glare, which the code declares a public nuisance under § 38-442.
Thornton Light Trespass and Glare Rule
Some RestrictionsThornton City Code § 38-442
(a)Exterior and interior lighting in all zoning districts shall be designed and installed so that all direct rays are confined to the site on which the lighting is located and so that adjacent residential properties are protected from glare which is deemed to be a public nuisance.(b)The installation or erection of any lighting which simulates, imitates or conflicts with warning signals, emergen...
Looking for Adams County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Thornton city rules.
Outdoor Lighting in Adams County →