How dark is the sky in Swansea, IL?

Swansea reads as suburban edge on this dataset's scale. A noticeable glow near the horizon. Brighter stars and constellations are easy to pick out; the Milky Way is washed out. Only 29.9% of the 3,206 cities measured here read darker than Swansea.

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.

The nearest darker sky to Swansea

Glen Carbon, IL, about 14 miles away as the crow flies, measures in the rural band, one step darker than Swansea. Actual driving distance will run longer than that straight-line figure.

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

Swansea against the rest of the dataset

Swansea, IL has a population of about 14,445, one of 3,206 US cities of 10,000 or more residents in this dataset. Among all 3,206 cities here, Swansea ranks 955 from darkest to brightest, 1 being the darkest measured.