Boise Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

18.30

Bortle class

Class 8 (Class 8)

Darkness Quotient

26%

Dataset

April 2026

City sky

Boise: The Practical Verdict

Boise, as a mid-size city in Idaho, suffers from substantial urban light pollution impacting astronomical observation. With a Bortle 8 classification, the city sky offers poor conditions for stargazers, severely limiting visibility of faint celestial objects. The brightest areas of the urban glow are toward the west, with the north-east being somewhat cleaner but still light-affected.

From Boise itself, the Milky Way is completely erased from visibility, leaving only the brightest targets such as the Moon, planets, and prominent stars for practical visual observation. Narrowband imaging can be attempted, but gradients and heavy sky background remain significant barriers for capturing detailed clarity in broadband astrophotography.

For those seeking darker skies for deep-sky observing, Elmore County lies to the south-east, about 80 km away. This nearby location offers a Bortle 3 sky, dramatically improving conditions for observing and imaging compared to Boise's urban environment.

At a Glance

Overall

Poor city sky - This is a poor city sky. The Milky Way is not visible and most deep-sky observing is unrealistic from the location itself.

Milky Way

Not visible - The Milky Way is erased by the bright urban sky background.

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

Elmore County, Idaho sits about 80 km south east and reaches Bortle 3, roughly 18x darker.

Good dark window

Boise'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 Boise?

No. Boise is a Bortle Class 8 sky with SQM 18.30, 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 Boise?

Boise is Bortle Class 8 (SQM 18.30), a poor city sky for astronomy.

Is Boise good for stargazing?

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

Is Boise good for astrophotography?

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

What can you observe from Boise?

Primary targets from Boise 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 Boise?

The closest meaningfully darker mapped site is Elmore County, Idaho, about 80 km south east of Boise, reaching Bortle 3.

When is the sky darkest in Boise?

The sky over Boise is darkest around January, December.

Is light pollution in Boise getting better or worse?

There is not yet enough long-term data to give a confident trend for Boise.

• Elmore County, Idaho

  Direction

  SE

  Distance (km)

  79.9

  SQM

  21.45

  Bortle

  3

• Lemhi County, Idaho

  Direction

  ENE

  Distance (km)

  252.9

  SQM

  21.75

  Bortle

  2

• Power County, Idaho

  Direction

  ESE

  Distance (km)

  261.6

  SQM

  21.66

  Bortle

  3