Dark Sky Rules: Castro Valley vs San Leandro
How do dark sky rules rules compare between Castro Valley, CA and San Leandro, CA?
Castro Valley and San Leandro have similar restriction levels.
Castro Valley, CA
Alameda County
East Alameda County supports dark sky preservation near Lick Observatory. Title 17 requires shielded full-cutoff fixtures in rural and hillside zones, stricter near the observatory influence area.
View full Castro Valley rules →San Leandro, CA
Alameda County
San Leandro zoning code requires shielded outdoor lighting in residential zones. No formal Dark Sky ordinance but spill/glare onto neighbors prohibited.
View full San Leandro rules →Key Facts Comparison
| Fact | Castro Valley | San Leandro |
|---|---|---|
| Observatory context | Lick Observatory influence | - |
| Fixture standard | Full-cutoff, no uplight | - |
| Color temperature | 2700K or lower preferred | - |
| Curfew | Typical 10-11 PM for non-essential | - |
| Stricter in | Rural and hillside zones | - |
| Shielding | - | Required residential |
| Design review | - | Commercial/MFR |
| Property line | - | ~0.5 fc max |
| IDA ordinance | - | None formal |
| Security light | - | Motion/timer preferred |
Highlighted rows indicate differences between cities.
Castro Valley FAQ
Does Alameda County require dark sky lighting everywhere?
No. Urban areas like Oakland and Hayward have less restrictive standards. Rural unincorporated areas near Sunol and Livermore have enhanced dark sky rules due to Lick Observatory proximity.
Are holiday lights allowed?
Yes, seasonal decorative lighting is typically exempt, though most dark sky ordinances encourage turning decorative lights off by 11 PM.
San Leandro FAQ
Is my floodlight legal?
Yes if shielded and not shining onto neighbors. Bare bulb glare may trigger a nuisance complaint.
Are commercial lots required to turn off lights at night?
Not blanket, but dark sky principles in design review often require lighting curfews or dimming.
Compare other topics
See how Castro Valley and San Leandro compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool