Diamond Bar, CA's night sky, measured from orbit

Diamond Bar reads as suburban on this dataset's scale. Light dome dominates much of the sky. Only the brightest stars and planets stand out clearly. That's brighter than 66.1% of the 3,206 US cities in this dataset.

Note the source: a satellite reading of upward light, not a visual Bortle scale reading. The two measure related but different things.

How far Diamond Bar is from a meaningfully darker sky

The closest place in this dataset with a meaningfully darker sky is Walnut, CA, roughly 3 miles away in a straight line, rated suburban edge. Road distance will be more.

Walnut, CA is itself still a measured city, not a designated dark-sky park, this only compares against the 3,206 places this dataset covers.

How Diamond Bar compares nationally

Diamond Bar, CA has a population of about 52,292, one of 3,206 US cities of 10,000 or more residents in this dataset. Diamond Bar places 2,109 of 3,206 cities in this dataset's darkest-to-brightest order.