How dark is the sky in Iceland?
Sky darkness for 8 towns and parks in Iceland, worked out from NASA satellite images of light at night (2025). 4 of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Skaftafell (21.93, Bortle 2), the brightest Reykjavík (17.59, 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 Iceland
- SkaftafellEast · Bortle 221.93
- JökulsárgljúfurNortheast · Bortle 321.85
- Snæfellsjökull National ParkWest · Bortle 321.81
- Thingvellir National ParkSouth · Bortle 421.17
Among the places on this site. Plenty of land between them is just as dark, with no town or park to name it by.
Darkest place in each region of Iceland
| Region | Places | Dark places Bortle 1 to 4 | Darkest place |
|---|---|---|---|
| Capital Region | 2 places | 0 dark | Mosfellsbær18.63 · Bortle 7 |
| East | 1 place | 1 dark | Skaftafell21.93 · Bortle 2 |
| Northeast | 2 places | 1 dark | Jökulsárgljúfur21.85 · Bortle 3 |
| South | 1 place | 1 dark | Thingvellir National Park21.17 · Bortle 4 |
| Southern Peninsula | 1 place | 0 dark | Reykjanesbær18.75 · Bortle 7 |
| West | 1 place | 1 dark | Snæfellsjökull National Park21.81 · Bortle 3 |