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

Mendocino County's strongest outdoor-lighting rules are in the Coastal Zone. The Coastal Zoning Code's Visual Resource and Special Treatment Areas chapter (Chapter 20.504) includes Section 20.504.035, Exterior Lighting Regulations, which require that exterior lighting be designed and installed so that it is shielded and directed downward (downcast) to minimize glare and light spill and to protect coastal views and the night sky. Section 20.504.015 designates Highly Scenic Areas, including the coast from the Ten Mile River estuary north to the Hardy Creek Bridge, where development must protect coastal views from public roads, trails, beaches and waters; coastal development permits in these areas commonly carry conditions requiring downcast, shielded lighting consistent with Section 20.504.035. These standards are administered through the Coastal Development Permit process. Outside the Coastal Zone, the County does not have a comprehensive county-wide dark-sky ordinance, but discretionary projects can still be conditioned to limit glare, and the rural character of inland Mendocino keeps ambient light low. The region is widely promoted for stargazing, but that reflects the rural landscape and coastal lighting standards rather than a single inland dark-sky law. Property owners on the coast should plan exterior lighting to be fully shielded and downward-directed, and should confirm specific conditions through Planning & Building Services and the Coastal Development Permit review.