How dark is the sky in Alberta?
Sky darkness for 25 towns and parks in Alberta, worked out from NASA satellite images of light at night (2025). 14 of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Wood Buffalo National Park (21.94, Bortle 2), the brightest Edmonton (17.24, 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 Alberta
- Wood Buffalo National ParkBortle 221.94
- Jasper National ParkBortle 321.89
- Willmore Wilderness ParkBortle 321.87
- Writing-on-Stone Provincial ParkBortle 321.84
- Dinosaur Provincial ParkBortle 321.80
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 Alberta
All 25 places in Alberta
Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Airdrie7Aspen Beach Provincial Park4Banff National Park4Bon Accord5Bow Valley Provincial Park4Bragg Creek Provincial Park4Calgary8Dinosaur Provincial Park3Dry Island Buffalo Jump Provincial Park4Edmonton8Elk Island National Park4Fort McMurray7Grande Prairie8Jasper National Park3Lethbridge8Medicine Hat7Midland Provincial Park4Red Deer8Sherwood Park8St. Albert8Waterton Lakes National Park4William A. Switzer Provincial Park4Willmore Wilderness Park3Wood Buffalo National Park2Writing-on-Stone Provincial Park3