Sioux Falls Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

17.81

Bortle class

Class 9 (Class 9)

Darkness Quotient

21%

Dataset

May 2026

Inner city sky

Sioux Falls: The Practical Verdict

Sioux Falls, a small city in South Dakota, is characterised by high light pollution. The overall sky quality here is rated as a severe urban sky, making deep-sky observation quite challenging. The primary limiting factor is the significant light dome, which obscures the Milky Way entirely.

From this location, astronomers can find satisfaction in observing the Moon, planets, and bright stars, along with some success in narrowband imaging. However, the sky conditions are unfavourable for visual deep-sky observing, reflection nebulae, or widefield views of the Milky Way.

For a drastic improvement in sky quality, head towards Spring Lake Township, south-east of here. It offers a Bortle 3 sky and is around 80 kilometres away, making it a prime destination for serious deep-sky observation.

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

Spring Lake Township, South Dakota sits about 79 km west north west and reaches Bortle 3, roughly 27x darker.

Good dark window

Sioux Falls'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 Sioux Falls?

No. Sioux Falls is a Bortle Class 9 sky with SQM 17.81, 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 Sioux Falls?

Sioux Falls is Bortle Class 9 (SQM 17.81), a severe urban sky for astronomy.

Is Sioux Falls good for stargazing?

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

Is Sioux Falls good for astrophotography?

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

What can you observe from Sioux Falls?

Primary targets from Sioux Falls 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 Sioux Falls?

The closest meaningfully darker mapped site is Centennial Township, Iowa, about 25 km south east of Sioux Falls, reaching Bortle 6.

When is the sky darkest in Sioux Falls?

The sky over Sioux Falls is darkest around January, December.

Is light pollution in Sioux Falls getting better or worse?

Long-term light pollution over Sioux Falls has been broadly stable across the available measurements.

• Centennial Township, Iowa

  Direction

  SE

  Distance (km)

  25

  SQM

  19.87

  Bortle

  6

• Virginia Township, South Dakota

  Direction

  SSE

  Distance (km)

  53.1

  SQM

  20.72

  Bortle

  5

• Spring Lake Township, South Dakota

  Direction

  WNW

  Distance (km)

  79.2

  SQM

  21.38

  Bortle

  3

• 5892, Iowa

  Direction

  ESE

  Distance (km)

  91.5

  SQM

  21.00

  Bortle

  4