How dark is the sky in Texas?
Sky darkness for 93 towns and parks in Texas, worked out from NASA satellite images of light at night (2025). 23 of them have skies of Bortle 4 or darker, where the Milky Way shows overhead. The darkest is Big Bend National Park (21.93, Bortle 2), the brightest Houston (16.87, 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 Texas
- Big Bend National ParkBortle 221.93
- Devils River State Natural AreaBortle 321.79
- Big Bend Ranch State ParkBortle 321.76
- Seminole Canyon State Park and Historic SiteBortle 321.75
- Caprock Canyons State Park and TrailwayBortle 321.74
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 Texas
All 93 places in Texas
Amber names are parks and certified dark-sky places. The figure is the Bortle class: 1 darkest, 9 city center.
Abilene7Alibates Flint Quarries National Monument4Allen8Amarillo8Amistad National Recreation Area5Arlington8Austin8Balmorhea State Park4Baytown8Beaumont8Big Bend National Park2Big Bend Ranch State Park3Big Thicket National Preserve5Brownsville8Caprock Canyons State Park and Trailway3Carrollton8Cedar Park8Celina7College Station8Colorado Bend State Park4Conroe8Copper Breaks State Park3Corpus Christi8Cypress8Dallas8Davis Mountains State Park3DeSoto8Denton8Devils River State Natural Area3Dripping Springs5Edinburg8El Paso8Enchanted Rock State Natural Area4Euless8Flower Mound8Fort Leaton State Historic Site4Fort Worth8Frisco8Galveston8Garland8Garner State Park4Georgetown8Goose Island State Park4Grand Prairie8Grapevine8Guadalupe Mountains National Park4Harlingen8Hill Country State Natural Area4Horseshoe Bay5Houston8Irving8Kickapoo Cavern State Park4Killeen8Lake Meredith National Recreation Area4Laredo8League City8Leander8Lewisville8Longhorn Cavern State Park4Longview8Lubbock8Mansfield8McAllen8McKinney8Mesquite8Midland8Mission8Missouri City8New Braunfels8Odessa8Padre Island National Seashore4Palmetto State Park4Pasadena8Pearland8Pedernales Falls State Park4Pflugerville8Plano8Port Arthur8Richardson8Round Rock8San Angelo8San Antonio8San Marcos8Seminole Canyon State Park and Historic Site3South Llano River State Park4Spring8Sugar Land8Temple8The Woodlands8Tyler8Victoria7Waco8Wichita Falls8