Dark Sky Rules: Cambridge vs Somerville
How do dark sky rules rules compare between Cambridge, MA and Somerville, MA?
Cambridge and Somerville have similar restriction levels.
Cambridge, MA
Middlesex County
Cambridge Zoning Ordinance requires outdoor lighting to be shielded and directed downward to minimize glare and light trespass, supporting Net Zero and energy efficiency goals.
View full Cambridge rules →Somerville, MA
Middlesex County
Somerville zoning requires full cutoff fixtures and limits outdoor lighting to 3000K color temperature in most districts. Uplighting is generally prohibited.
View full Somerville rules →Key Facts Comparison
| Fact | Cambridge | Somerville |
|---|---|---|
| Fixture standard | Full cutoff shielded | Full cutoff required |
| Direction | Downward | - |
| Residential trespass | 0.1 fc at line | - |
| Commercial trespass | 1.0 fc at line | - |
| Complaints | Inspectional Services | - |
| Color temperature | - | 3000K maximum typical |
| Uplighting | - | Generally prohibited |
| Property line | - | 0.5 fc maximum |
| Streetlights | - | 3000K LED citywide |
Highlighted rows indicate differences between cities.
Cambridge FAQ
Are full-cutoff fixtures required?
Yes, Cambridge requires shielded, downward-directed outdoor lighting to reduce glare and trespass.
Can I use a floodlight in my backyard?
Yes if aimed downward and not creating glare onto neighbors or streets; motion activated is preferred.
Somerville FAQ
Can I install a bright 5000K floodlight on my garage?
5000K exceeds Somerville's warm-light preference. Choose a 3000K or lower fixture with a shielded, downward-aimed design to meet zoning and avoid neighbor complaints.
Are holiday string lights regulated?
Temporary seasonal lighting for 60 days or less is typically exempt, but lights aimed into a neighbor's bedroom window can still be cited as a nuisance.
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