Dark Sky Rules: Altadena vs Pomona
How do dark sky rules rules compare between Altadena, CA and Pomona, CA?
Pomona has fewer restrictions than Altadena.
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 →Pomona, CA
Los Angeles County
Pomona does not have a specific dark-sky ordinance. General light nuisance provisions in the municipal code may apply. Outdoor lighting for new development is reviewed through the planning process.
View full Pomona rules →Key Facts Comparison
| Fact | Altadena | Pomona |
|---|---|---|
| ROLD | Effective since 2012 | - |
| Shielding | All outdoor lighting must be fully shielded | - |
| Mercury Vapor | Prohibited | - |
| Applies To | Rural unincorporated areas | - |
| Dark-Sky Ordinance | - | None specific to Pomona |
| New Development | - | Lighting reviewed in planning |
| Nuisance | - | General nuisance code may apply |
| State | - | No CA statewide dark-sky mandate |
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.
Pomona 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 Pomona code enforcement if outdoor lights from adjacent properties create a nuisance.
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