Outdoor Lighting in Sonoma County, CA (2026)

2 county-level rules, plus city-specific rules for 2 cities in Sonoma County, California.

Verified from official government sources

Note: These county rules apply to unincorporated areas of Sonoma County. If you live within an incorporated city, that city's own rules apply: see the city list below.

Dark Sky Rules

Homes and site development in Sonoma County's Taylor/Sonoma/Mayacamas Mountains (LG/MTN) combining zone must use downward-facing, fully shielded exterior lights capped at 1,000 lumens per fixture, with no more than 1.0 lux crossing the property line. Flood lights are prohibited, and any security lighting must be motion-sensor activated only.

Sonoma County Mountain Zone Dark Sky Lighting Rules

Significant Restrictions

Sonoma County Code § 26-90-120(c)(2)(d)

d. Lighting, Exterior. 1. Exterior lighting shall be downward facing, fully shielded, and located at the lowest possible point to the ground to prevent glare and light pollution. 2. Light fixtures shall not be located at the periphery of the property and shall not spill over onto adjacent properties or into the night sky. 3. Luminaires shall have a maximum output of one thousand (1,000) lumens ...

Full ordinance details →Official source ↗

Light Trespass & Shielding

In the Taylor/Sonoma/Mayacamas Mountains combining zone, exterior lights cannot spill onto adjacent properties or into the night sky. Total illuminance past the property line is capped at 1.0 lux, each luminaire at 1,000 lumens, and flood lights are not allowed at all.

Sonoma County Mountain Zone Light Trespass Limits

Heavy Restrictions

Sonoma County Code § 26-90-120(c)(2)(d)

Lighting, Exterior. 1. Exterior lighting shall be downward facing, fully shielded, and located at the lowest possible point to the ground to prevent glare and light pollution. 2. Light fixtures shall not be located at the periphery of the property and shall not spill over onto adjacent properties or into the night sky. 3. Luminaires shall have a maximum output of one thousand (1,000) lumens per...

Full ordinance details →Official source ↗

Outdoor Lighting by City in Sonoma County

2 cities in Sonoma County have their own outdoor lighting rules. Each link goes to that city's dedicated page with code citations.

Santa RosaPop. 178,127

2 verified rules • Dark Sky Rules, Light Trespass & Shielding

PetalumaPop. 59,776

3 verified rules • Billboard Lighting, Dark Sky Rules

All Sonoma County ordinances

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