Pima County, AZ Outdoor Lighting: Light Trespass (2026)

The Pima County Outdoor Lighting Code (Chapter 18.81) addresses light trespass as part of its comprehensive dark-sky protection framework. All outdoor luminaires must be fully shielded (full-cutoff design) to prevent light from spilling above the horizontal plane or onto adjacent properties. The code limits the amount of light measured at the property line -- in residential zones, light trespass at the property boundary must not exceed 0.5 footcandles. Fixtures must be aimed and positioned so the primary cone of light falls entirely within the property boundary. Floodlights, security lights, and landscape lighting must be adjustable and aimed downward. Glare from commercial properties (parking lots, signage, building facades) onto residential properties is a common enforcement target. The code applies to all new installations and requires compliance when existing fixtures are replaced. Near Kitt Peak (Zone A), enforcement is especially rigorous and even minor trespass triggers rapid response. Residents may file light trespass complaints with Pima County Code Enforcement. The county may require photometric studies for commercial developments to verify compliance.