Dark Sky Rules: Altadena vs Santa Monica
How do dark sky rules rules compare between Altadena, CA and Santa Monica, CA?
Altadena and Santa Monica have similar restriction levels.
Altadena, CA
Los Angeles County
LA County's Rural Outdoor Lighting District (ROLD) ordinance, effective 2012, requires fully shielded outdoor lighting and prohibits light trespass in designated rural unincorporated areas. The ROLD covers mountain and rural communities. Mercury vapor lights and drop-down lenses are prohibited.
View full Altadena rules →Santa Monica, CA
Los Angeles County
Santa Monica regulates outdoor lighting under SMMC §9.21.080. While not a standalone dark sky ordinance, the city addresses light pollution through zoning standards. CALGreen Code §5.106.8 also applies to new commercial development.
View full Santa Monica rules →Key Facts Comparison
| Fact | Altadena | Santa Monica |
|---|---|---|
| ROLD | Effective since 2012 | - |
| Shielding | All outdoor lighting must be fully shielded | - |
| Mercury Vapor | Prohibited | - |
| Applies To | Rural unincorporated areas | - |
| Code | - | SMMC §9.21.080 |
| Dark Sky Ordinance | - | No standalone ordinance |
| CALGreen | - | §5.106.8 light pollution standards |
| New Development | - | Shielding and CCT limits apply |
Highlighted rows indicate differences between cities.
Altadena FAQ
Does LA County have dark sky rules?
Yes. The Rural Outdoor Lighting District (ROLD) ordinance restricts outdoor lighting in rural unincorporated areas. It requires full shielding, warm color temperatures, and maximum lumen limits to reduce light pollution.
Am I in the ROLD?
The ROLD covers rural unincorporated communities in the Santa Monica Mountains, northern LA County, and other designated areas. Check with the Department of Regional Planning at (213) 974-6411 or review the ROLD boundary maps on planning.lacounty.gov.
What type of outdoor lights are allowed in ROLD areas?
Fully shielded fixtures (no upward light emission) with warm white color temperature (below 3000K recommended). Maximum lumen output varies by fixture type and location. All new fixtures must be ROLD-compliant.
Santa Monica FAQ
What does fully shielded mean?
The fixture must direct all light downward with no light emitted above the horizontal plane. This prevents glare and sky glow while still providing ground illumination.
Can my neighbor's lights shine into my yard?
Most codes prohibit light trespass onto neighboring properties. Contact Santa Monica code enforcement if outdoor lights from adjacent properties create a nuisance.
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