Cannabis Regulations in Thornton, CO (2026)
3 verified cannabis regulations for Thornton, Colorado, sourced directly from the municipal code and official government pages.
Verified from official government sources
Home Cultivation
Thornton limits home marijuana cultivation to a primary residence or its detached accessory structure, caps growth at six plants per adult and 12 per lot, restricts the growing area to 32 or 50 square feet, and bans outdoor grows entirely. Section 38-298 also mandates a locked enclosure, LED or fluorescent lighting only, and odor control.
Thornton's Home Marijuana Cultivation Rules
Significant RestrictionsThornton, CO City Code § 38-298(b)(1)-(2)
(b)Cultivation restrictions. It shall be unlawful for any person to cultivate, attempt to cultivate, or in any way cause, allow, or permit the cultivation of marijuana in violation of any of the following:(1)Cultivation location. ...marijuana may only be cultivated within a person's primary residence or detached accessory structure on the lot where the primary residence is located, and only on ...
Dispensary Zoning
Thornton opted in to retail marijuana licensing under its home-rule authority, but the city caps the entire market at four marijuana store locations and allows no more than one per each of the city's four geographical quadrants, so most sites in the city are off-limits regardless of zoning.
Thornton Marijuana Store Location Limits
Significant RestrictionsThornton City Code § 42-718(a)
The authority shall approve licenses for no more than four marijuana store locations in the city in all, and no more than one marijuana store location per geographical quadrant.
Buffer Zones
Every marijuana establishment application filed in Thornton must include a scaled area map proving the proposed site sits at least 1,000 feet from any school and 500 feet from any licensed child care facility or drug and alcohol treatment facility, measured out from the building's footprint, under the city's marijuana licensing code.
Thornton Marijuana Business Buffer Zones
Significant RestrictionsThornton City Code § 42-715(d)(4)
Area map, drawn to scale or depicted in a satellite photograph on 8.5" x 11" paper indicating a 1,000-foot buffer area measured out from the footprint of the building demonstrating that the premises shall be at least 1,000 feet from any type of school as defined in the Colorado Retail Marijuana Code, and at least 500 feet from any licensed child care facility, and any public or private treatmen...
Looking for Adams County county-wide rules?
County ordinances apply to unincorporated areas and may supplement Thornton city rules.
Cannabis Regulations in Adams County →