Iowa dark-sky map — light pollution by town
Iowa has 40 towns rated for light pollution here, from its darkest — Fort Madison (Bortle 6) — to its brightest city cores. 0 rate as genuinely dark or rural sky (Bortle 4 or better). Sort the table by darkness to find the best stargazing near you, then open any town for its exact rating, what you can see, the nearest darker skies to drive to, and tonight's live Moon, cloud, and aurora conditions. Ratings are a VIIRS satellite proxy for planning, not survey-grade sky-brightness readings.
- Towns rated
- 40
- Darkest town
- Fort Madison
- Genuinely dark towns
- 0
0 rate as genuinely dark or rural sky (about Bortle 4 or better).
All Iowa towns by darkness
Darkest sky first. Click a column heading to sort, or filter by name. A satellite reading, not a survey-grade measurement — and the real dark skies are usually a short drive out of any town.
| Sky | |||
|---|---|---|---|
| Fort Madison | 6 | Bright suburban sky | 11 |
| Storm Lake | 6 | Bright suburban sky | 16 |
| Grimes | 6 | Bright suburban sky | 19 |
| Norwalk | 6 | Bright suburban sky | 19 |
| Cedar Rapids | 7 | Suburban / urban transition | 21 |
| Ames | 7 | Suburban / urban transition | 22 |
| Cedar Falls | 7 | Suburban / urban transition | 22 |
| Urbandale | 7 | Suburban / urban transition | 24 |
| Spencer | 7 | Suburban / urban transition | 25 |
| Boone | 7 | Suburban / urban transition | 26 |
| Indianola | 7 | Suburban / urban transition | 26 |
| Waverly | 7 | Suburban / urban transition | 26 |
| Marion | 7 | Suburban / urban transition | 27 |
| Burlington | 7 | Suburban / urban transition | 27 |
| Waukee | 7 | Suburban / urban transition | 28 |
| Altoona | 7 | Suburban / urban transition | 29 |
| North Liberty | 7 | Suburban / urban transition | 29 |
| West Des Moines | 7 | Suburban / urban transition | 29 |
| Keokuk | 7 | Suburban / urban transition | 31 |
| Fort Dodge | 7 | Suburban / urban transition | 34 |
| Muscatine | 7 | Suburban / urban transition | 34 |
| Clive | 7 | Suburban / urban transition | 34 |
| Waterloo | 7 | Suburban / urban transition | 36 |
| Newton | 7 | Suburban / urban transition | 36 |
| Bettendorf | 7 | Suburban / urban transition | 36 |
| Ankeny | 7 | Suburban / urban transition | 37 |
| Oskaloosa | 7 | Suburban / urban transition | 38 |
| Coralville | 7 | Suburban / urban transition | 38 |
| Johnston | 7 | Suburban / urban transition | 39 |
| Marshalltown | 8 | City sky | 40 |
| Ottumwa | 8 | City sky | 41 |
| Clinton | 8 | City sky | 42 |
| Pella | 8 | City sky | 42 |
| Mason City | 8 | City sky | 47 |
| Council Bluffs | 8 | City sky | 55 |
| Iowa City | 8 | City sky | 66 |
| Dubuque | 8 | City sky | 80 |
| Des Moines | 8 | City sky | 84 |
| Davenport | 8 | City sky | 86 |
| Sioux City | 9 | Inner-city sky | 133 |
Frequently asked questions
- Where are the darkest skies in Iowa?
- The darkest town tracked here is Fort Madison. Sort the table on this page by darkness to see the full ranking, from the most rural, star-filled skies down to the brightest city cores.
- How many dark-sky towns does Iowa have?
- Of 40 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.
Explore
Learn to read the Bortle scale, check the meteor shower calendar, or search all towns from the home page.