Harrisburg, SD: how dark is the sky here?
Harrisburg reads as suburban on this dataset's scale. Light dome dominates much of the sky. Only the brightest stars and planets stand out clearly. Harrisburg's sky is brighter than 54.2% of the 3,206 cities in this dataset.
This comes from a satellite measuring light radiating upward, not a person's eyes on the ground, so it isn't the same as a Bortle class, though the two track each other closely.
How far Harrisburg is from a meaningfully darker sky
13 miles from Harrisburg, straight-line, sits Brandon, SD, the nearest city here with a darker sky than Harrisburg's own suburban band.
Brandon, SD is itself still a measured city, not a designated dark-sky park, this only compares against the 3,206 places this dataset covers.
How Harrisburg compares nationally
Harrisburg, SD has a population of about 10,203, one of 3,206 US cities of 10,000 or more residents in this dataset. Harrisburg places 1,727 of 3,206 cities in this dataset's darkest-to-brightest order.