Rancho Cucamonga, CA Outdoor Lighting: Dark Sky Rules (2026)

Outdoor lighting in Rancho Cucamonga is regulated by Development Code Section 17.58 (Outdoor Lighting Standards), which requires all new outdoor lighting to be fully shielded, downward-directed, and designed to prevent spillover and skyglow. The ordinance addresses both light trespass onto neighboring properties and visual impacts to the night sky, supporting the foothill residential character and nearby Mount San Antonio observation areas. Fixture requirements include full-cutoff or shielded designs (IDA-approved where feasible), color temperature typically capped at 3000K or lower to reduce blue-light skyglow per Title 24 Energy Code recommendations, and maximum lumen levels based on land use. Commercial properties must submit photometric plans showing foot-candle levels at property lines not exceeding 0.5 fc at residential boundaries. Unshielded floodlights, wall packs with exposed bulbs, and upward-facing decorative lighting are prohibited in most districts. Exemptions exist for holiday lighting (November 1 to January 15), low-voltage landscape lighting under 20 watts per fixture, and temporary event lighting with a permit.