Portland, TX Night Sky Brightness
Portland, TX's night sky, measured from orbit
Portland 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 38.6% of the 3,206 cities measured here read darker than Portland.
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 Portland is from a meaningfully darker sky
142 miles from Portland, straight-line, sits Helotes, TX, the nearest city here with a darker sky than Portland's own suburban edge band.
Helotes, TX is itself still a measured city, not a designated dark-sky park, this only compares against the 3,206 places this dataset covers.
How Portland compares nationally
Portland, TX counts roughly 20,725 residents, among the 3,206 US cities this site tracks. Portland's position, 1,230 of 3,206, darkest to brightest, comes from the sampling method the methodology guide sets out.