San Antonio Stargazing & Astronomy Report

Light pollution and stargazing locations near San Antonio

City
San Antonio
Country
United States
Latitude
29.4241
Longitude
-98.4936

Key Sky Quality Metrics

SQM (mag/arcsec²)
17.27
Bortle class
Class 9 (Class 9)
Darkness Quotient
18%
Dataset
August 2026

Inner city sky

San Antonio: The Practical Verdict

San Antonio, located in Texas, is a major city with a population of approximately 2.5 million, which results in extreme light pollution. The city offers a "Severe urban sky," making it a challenging environment for stargazers. The overwhelming light dome means that the Milky Way is not visible, and the best observational targets are restricted to the Moon, planets, and very bright stars.

With such bright skies, only the brightest celestial objects such as the Moon, planets, and certain bright stars are discernible without difficulty. Deep-sky observing is severely hampered, and targets like faint nebulae or the Milky Way are off the table. For those interested in photography, narrowband imaging needs careful attention due to the light pollution background.

For an improved stargazing experience, head to Calhoun County roughly 225 km south-east. This site offers a considerably darker sky, where serious deep-sky observing becomes feasible, especially on clearer nights.

At a Glance

Overall
Severe urban sky - This is a severely light-polluted urban sky. Only the Moon, planets, bright stars, and a few specialist targets remain practical.
Milky Way
Not visible - The Milky Way is not visible from this sky.
Best targets from here
Moon, planets, bright stars, double stars, solar system events, narrowband imaging only with care
Do not prioritise
visual deep-sky observing, broadband galaxies, reflection nebulae, widefield Milky Way
Best nearby upgrade
Calhoun County, Texas sits about 223 km south east and reaches Bortle 3, roughly 55x darker.
Good dark window
San Antonio's longest dark windows fall in December and January, with the shortest nights around June and July. Plan deep-sky sessions around the autumn and winter months for the best combination of long nights and true astronomical darkness.

Frequently Asked Questions

Can you see the Milky Way from San Antonio?

No. San Antonio is a Bortle Class 9 sky with SQM 17.27, so the Milky Way is not visible from the city. For Milky Way photography, look for a Bortle 4 or darker site.

What Bortle class is San Antonio?

San Antonio is Bortle Class 9 (SQM 17.27), a severe urban sky for astronomy.

Is San Antonio good for stargazing?

Not for serious deep-sky observing. San Antonio is a severe urban sky where the Moon, planets, and a handful of bright targets are the realistic options from the city itself.

Is San Antonio good for astrophotography?

Broadband deep-sky imaging is heavily compromised from San Antonio and a Bortle 4 or darker site is strongly recommended. Even narrowband imaging is difficult from San Antonio without careful processing.

What can you observe from San Antonio?

Primary targets from San Antonio include Moon, planets, bright stars, double stars, solar system events. Targets such as visual deep-sky observing, broadband galaxies, reflection nebulae are not realistic from this sky.

Where are darker skies near San Antonio?

The closest meaningfully darker mapped site is Byrd Road, Texas, about 52 km south south east of San Antonio, reaching Bortle 6.

When is the sky darkest in San Antonio?

The sky over San Antonio is darkest around January, December.

Is light pollution in San Antonio getting better or worse?

Long-term light pollution over San Antonio has been broadly stable across the available measurements.

north - poor

A bright dome of skyglow sits on the north horizon. Faint stars are suppressed up to roughly 25 degrees elevation.

north-north-east - marginal

A soft but obvious glow marks the north-north-east horizon. The lowest 15-20 degrees of sky in this direction are degraded.

north-east - poor

Strong artificial brightening to the north-east. Faint and mid-brightness stars near the horizon are absent.

east-north-east - marginal

Moderate brightening on the east-north-east horizon. Star counts at low elevation here are reduced.

east - marginal

A soft but obvious glow marks the east horizon. The lowest 15-20 degrees of sky in this direction are degraded.

east-south-east - marginal

The east-south-east horizon is brighter than natural. Faint stars are suppressed up to roughly 15-20 degrees elevation.

south-east - fair

Mild brightening on the south-east horizon. Faint stars at the very lowest elevation are dimmed; otherwise unaffected.

south-south-east - marginal

Persistent skyglow on the south-south-east horizon. Faint stars near the ground in this direction are lost.

south - marginal

Moderate brightening on the south horizon. Star counts at low elevation here are reduced.

south-south-west - marginal

A soft but obvious glow marks the south-south-west horizon. The lowest 15-20 degrees of sky in this direction are degraded.

south-west - marginal

Moderate brightening on the south-west horizon. Star counts at low elevation here are reduced.

west-south-west - marginal

The lower west-south-west sky is moderately light-polluted. Useful for bright targets above about 20 degrees only.

west - poor

The west horizon is bright with artificial light. Only stars brighter than magnitude 3 are visible at low elevation.

west-north-west - marginal

Persistent skyglow on the west-north-west horizon. Faint stars near the ground in this direction are lost.

north-west - poor

Bright skyglow dominates the lower north-west sky. This direction is not suitable for faint-object work at low elevation.

north-north-west - marginal

The north-north-west horizon is brighter than natural. Faint stars are suppressed up to roughly 15-20 degrees elevation.

zenith - poor

Overhead is dominated by skyglow. Only the brightest stars and planets are clear.

  • Byrd Road, Texas
    Direction
    SSE
    Distance (km)
    51.6
    SQM
    19.89
    Bortle
    6
  • Madrone Road, Texas
    Direction
    NNE
    Distance (km)
    62.5
    SQM
    19.85
    Bortle
    6
  • Cologne Road, Texas
    Direction
    ESE
    Distance (km)
    155.9
    SQM
    20.62
    Bortle
    5
  • Calhoun County, Texas
    Direction
    SE
    Distance (km)
    222.5
    SQM
    21.63
    Bortle
    3
  • County Road 95, Texas
    Direction
    SSE
    Distance (km)
    196.8
    SQM
    20.62
    Bortle
    5
  • Jackson County, Texas
    Direction
    ESE
    Distance (km)
    186.4
    SQM
    20.10
    Bortle
    6