Glen Ellyn, IL Night Sky Brightness
Glen Ellyn, IL's night sky, measured from orbit
Glen Ellyn's sky measures suburban here. Light dome dominates much of the sky. Only the brightest stars and planets stand out clearly. Glen Ellyn's sky is brighter than 59.6% of the 3,206 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, explained in the Bortle scale guide.
How far Glen Ellyn is from a meaningfully darker sky
5 miles from Glen Ellyn, straight-line, sits Winfield, IL, the nearest city here with a darker sky than Glen Ellyn's own suburban band.
Winfield, IL is itself still a measured city, not a designated dark-sky park, this only compares against the 3,206 places this dataset covers.
How Glen Ellyn compares nationally
About 28,872 people live in Glen Ellyn, IL, sized enough to appear in this dataset of 3,206 incorporated US cities. Glen Ellyn's position, 1,902 of 3,206, darkest to brightest, comes from the sampling method the methodology guide sets out.