How dark is the sky in Georgia?
Sky darkness for 26 towns and parks in Georgia, worked out from NASA satellite images of light at night (2025). 7 of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Stephen C. Foster State Park (21.43, Bortle 4), the brightest Atlanta (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 Georgia
- Stephen C. Foster State ParkBortle 421.43
- Kolomoki Mounds State ParkBortle 421.32
- Florence Marina State ParkBortle 421.07
- George T. Bagby State ParkBortle 421.00
- Chattahoochee-Oconee National ForestBortle 420.84
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 Georgia
All 26 places in Georgia
Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Albany8Alpharetta8Athens8Atlanta8Brookhaven8Chattahoochee-Oconee National Forest4Columbus8Cumberland Island National Seashore4F. D. Roosevelt State Park4Florence Marina State Park4Fort Frederica National Monument5Fort Pulaski National Monument5George T. Bagby State Park4Johns Creek8Kolomoki Mounds State Park4Macon8Marietta8Roswell8Sandy Springs8Savannah8Smyrna8South Fulton6Stephen C. Foster State Park4Stonecrest8Valdosta7Warner Robins7