Castle Rock, CO Night Sky Brightness
Castle Rock, CO's night sky, measured from orbit
Satellite radiance puts Castle Rock in the suburban band. Light dome dominates much of the sky. Only the brightest stars and planets stand out clearly. Only 50.1% of the 3,206 cities measured here read darker than Castle Rock.
Note the source: a satellite reading of upward light, not a visual Bortle scale reading. The two measure related but different things, explained in the Bortle scale guide.
How far Castle Rock is from a meaningfully darker sky
Castle Pines, CO, about 6 miles away as the crow flies, measures in the suburban edge band, one step darker than Castle Rock. Actual driving distance will run longer than that straight-line figure.
Castle Pines, CO is itself still a measured city, not a designated dark-sky park, this only compares against the 3,206 places this dataset covers.
How Castle Rock compares nationally
Castle Rock, CO counts roughly 83,213 residents, among the 3,206 US cities this site tracks. Castle Rock's position, 1,598 of 3,206, darkest to brightest, comes from the sampling method the methodology guide sets out.