Colusa County, CA Outdoor Lighting: Dark Sky Rules (2026)

' It applies to outdoor lighting in residential, commercial, industrial, and special-purpose classifications (and to lighting in other classifications adjacent to residential or commercial classifications), but not to publicly owned facilities or public rights-of-way. Under the Lighting Standards (Sec. 010): all outdoor lighting must be located, shielded, and directed so no direct light falls outside the property line or into the public right-of-way (Light Trespass); except where exempt, all outdoor lighting must be 'constructed with full shielding and/or recessed,' directed downward and away from adjoining properties, and fixtures higher than 6 feet above ground must limit the cone of direct illumination to 60 degrees or less; lighting must be the minimum level needed for safety, and moving, flashing, or animated lighting requires a Use Permit; and fixtures must be energy-efficient with a rated average bulb life of at least 10,000 hours.

Holiday lights, fossil-fuel flame fixtures, official emergency/temporary lighting, and lighting for permitted special events are exempt (Sec. 020). Prohibited lighting (Sec. 030) includes neon band lighting (except as permitted), search/laser lights (except emergency or permitted special events), hazardous fixtures, illumination of entire buildings, and roof-mounted lighting except for security. While the county does not call this a formal 'dark sky' ordinance, the full-shielding and night-sky language functions as one. Confirm details with Colusa County Planning & Building.