Montana dark-sky map — light pollution by town
Montana has 7 towns rated for light pollution here, from its darkest — Bozeman (Bortle 7) — to its brightest city cores, with 0 rating as genuinely dark or rural sky (Bortle 4 or better). Every town is listed with the nearest measurably darker town to drive to. It also holds 1 certified International Dark Sky Place, listed below with the nearest rated town to each. Ratings are a VIIRS satellite proxy, not survey-grade sky-brightness readings.
- Towns rated
- 7
- Darkest town
- Bozeman
- Genuinely dark towns
- 0
- Certified dark-sky places
- 1
0 rate as genuinely dark or rural sky (about Bortle 4 or better).
Certified dark-sky places in Montana
One site in Montana holds an International Dark Sky Place certification — awarded for actively protecting the night sky, not measured from orbit like the town ratings below. What each designation means →
| Place | Designation | Coordinates | Nearest rated town | Distance | That town's sky |
|---|---|---|---|---|---|
| Waterton-Glacier International Peace Park | Dark Sky Park | 48.996°N, 113.904°W | Kalispell | 58 mi | B7 |
All Montana towns by darkness
Darkest sky first, each with the nearest measurably darker town to drive to. Sort or filter below.
| Sky | Nearest darker sky | |||
|---|---|---|---|---|
| Bozeman | 7 | Suburban / urban transition | 26 | Ammon, ID — B6, 160 mi |
| Butte | 7 | Suburban / urban transition | 30 | Idaho Falls, ID — B6, 175 mi |
| Kalispell | 7 | Suburban / urban transition | 32 | Cheney, WA — B6, 160 mi |
| Helena | 7 | Suburban / urban transition | 40 | Ammon, ID — B6, 215 mi |
| Great Falls | 8 | City sky | 56 | Helena — B7, 72 mi |
| Missoula | 8 | City sky | 56 | Butte — B7, 92 mi |
| Billings | 8 | City sky | 96 | Sheridan, WY — B7, 100 mi |
Frequently asked questions
- Where are the darkest skies in Montana?
- The darkest town tracked here is Bozeman, but the genuinely dark skies in Montana are its 1 certified International Dark Sky Place — Waterton-Glacier International Peace Park — listed further down with the nearest rated town to each.
- How many dark-sky towns does Montana have?
- Of 7 towns rated here, 0 rate as genuinely dark or rural sky (about Bortle 4 or better) — good for seeing the Milky Way on a clear, moonless night.
- How are these light-pollution ratings measured?
- From VIIRS 2024 annual-average satellite night-lights, sampled at each town's center and mapped to a darkness class and an estimated Bortle band. It is a satellite upward-radiance proxy for planning, not a survey-grade sky-brightness reading. See the methodology page for details.
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