Portsmouth, OH Night Sky Brightness
Portsmouth, OH's night sky, measured from orbit
Portsmouth's sky measures rural here. Little local light dome. Most stars are visible; the Milky Way is faint but often findable away from town lights. That's brighter than 3% of the 3,206 US 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 Portsmouth is from a meaningfully darker sky
The closest place in this dataset with a meaningfully darker sky is Fort Oglethorpe, GA, roughly 293 miles away in a straight line, rated dark sky. Road distance will be more.
Fort Oglethorpe, GA is itself still a measured city, not a designated dark-sky park, this only compares against the 3,206 places this dataset covers.
How Portsmouth compares nationally
Portsmouth, OH has a population of about 17,489, one of 3,206 US cities of 10,000 or more residents in this dataset. Portsmouth's position, 98 of 3,206, darkest to brightest, comes from the sampling method the methodology guide sets out.