How dark is the sky in Indiana?
Sky darkness for 25 towns and parks in Indiana, worked out from NASA satellite images of light at night (2025). 5 of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Turkey Run State Park (20.77, Bortle 4), the brightest Indianapolis (17.09, Bortle 8).
19
Bortle class, 1 pristine to 9 city center
park or dark-sky place
city
Numbers like 21.95 or 16.97 are the brightness of the sky overhead on a clear, moonless night, in mag/arcsec². The scale runs backwards: a lower number means a brighter sky, from about 22 for a natural sky to about 17 in a city center.
How the readings are made
Darkest skies in Indiana
- Turkey Run State ParkBortle 420.77
- Shades State ParkBortle 420.73
- Hoosier National ForestBortle 420.68
- Brown County State ParkBortle 420.57
- Shakamak State ParkBortle 420.55
Among the places on this site. Plenty of land between them is just as dark, with no town or park to name it by.
Brightest city skies in Indiana
All 25 places in Indiana
Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Anderson7Beverly Shores5Bloomington8Brown County State Park4Carmel8Elkhart8Evansville8Fishers8Fort Wayne8Gary8Greenwood8Hammond8Hoosier National Forest4Indiana Dunes National Park7Indianapolis8Kokomo7Lafayette8Muncie8Noblesville8Potawatomi Wildlife Park5Shades State Park4Shakamak State Park4South Bend8Terre Haute8Turkey Run State Park4