How dark is the sky in Costa Mesa, CA?

Costa Mesa reads as urban on this dataset's scale. Sky glow overhead most nights. Typically only planets, the Moon, and a handful of the brightest stars are visible. That's brighter than 89.5% of the 3,206 US cities in this dataset.

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.

How far Costa Mesa is from a meaningfully darker sky

The closest place in this dataset with a meaningfully darker sky is Fountain Valley, CA, roughly 4 miles away in a straight line, rated suburban. Road distance will be more.

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

Costa Mesa against the rest of the dataset

Costa Mesa, CA counts roughly 109,131 residents, among the 3,206 US cities this site tracks. Among all 3,206 cities here, Costa Mesa ranks 2,854 from darkest to brightest, 1 being the darkest measured.