San Marino, CA Night Sky Brightness
How dark is the sky in San Marino, CA?
San Marino's sky measures suburban edge here. A noticeable glow near the horizon. Brighter stars and constellations are easy to pick out; the Milky Way is washed out. Only 43.5% of the 3,206 cities measured here read darker than San Marino.
Worth remembering: this is satellite radiance, not a ground observation. A true Bortle rating needs a human eye at night, this is the closest large-scale substitute, covered fully in the Bortle scale guide.
Where to go for a darker sky near San Marino
The closest place in this dataset with a meaningfully darker sky is Sierra Madre, CA, roughly 5 miles away in a straight line, rated rural. Road distance will be more.
Sierra Madre, CA is itself still a measured city, not a designated dark-sky park, this only compares against the 3,206 places this dataset covers.
San Marino against the rest of the dataset
San Marino, CA counts roughly 12,105 residents, among the 3,206 US cities this site tracks. Ranked against the other 3,206 cities here by the methodology guide's own sampling, San Marino comes in at 1,388, darkest to brightest.