Duncan, OK Night Sky Brightness
How dark is the sky in Duncan, OK?
Duncan's sky measures suburban edge here. A noticeable glow near the horizon. Brighter stars and constellations are easy to pick out; the Milky Way is washed out. Duncan's sky is brighter than 27.3% of the 3,206 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, covered fully in the Bortle scale guide.
How far Duncan is from a meaningfully darker sky
The closest place in this dataset with a meaningfully darker sky is Norman, OK, roughly 63 miles away in a straight line, rated rural. Road distance will be more.
Norman, OK is itself still a measured city, not a designated dark-sky park, this only compares against the 3,206 places this dataset covers.
Duncan against the rest of the dataset
About 23,174 people live in Duncan, OK, sized enough to appear in this dataset of 3,206 incorporated US cities. Ranked against the other 3,206 cities here by the methodology guide's own sampling, Duncan comes in at 871, darkest to brightest.