Cairns Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

19.06

Bortle class

Class 7 (Class 7)

Darkness Quotient

34%

Dataset

April 2026

Suburban/urban transition

Cairns: The Practical Verdict

Cairns is a small city nestled in Queensland, Australia, combining urban life with its tropical locale. Unfortunately for stargazers, the city's sky suffers from high light pollution, significantly impairing views of faint celestial objects. As such, observing here is quite limited without travelling to darker skies.

Under Cairns' suburban sky, the Milky Way is not visible, replaced by an orange-tinted dome from the pervasive urban glow. Observing efforts should focus on bright targets like the Moon, planets, and brighter open clusters. Deep-sky imaging might still be possible with narrowband filters but lacks richness due to the light backdrop.

Significantly darker skies await just a short drive away. Bellenden Ker, positioned around 45 km south-south-east of Cairns, offers class 3 Bortle conditions and vastly improved visibility, making it an appealing choice for deeper explorations of the night sky.

At a Glance

Overall

Poor urban/suburban sky - This is a poor sky for astronomy. The Moon, planets, and a few bright objects remain viable, but deep-sky work is difficult.

Milky Way

Not visible - The Milky Way is not realistically visible from this level of light pollution.

Best targets from here

Moon, planets, bright double stars, bright open clusters, narrowband imaging with careful processing

Do not prioritise

visual deep-sky observing, broadband galaxies, reflection nebulae, Milky Way photography

Best nearby upgrade

Bellenden Ker, Queensland sits about 45 km south south east and reaches Bortle 3, roughly 8.2x darker.

Good dark window

Cairns retains astronomical darkness throughout the year, so seasonality is less extreme than at higher latitudes. The main limitation is light pollution, not the length of the dark window.

Frequently Asked Questions

Can you see the Milky Way from Cairns?

No. Cairns is a Bortle Class 7 sky with SQM 19.06, 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 Cairns?

Cairns is Bortle Class 7 (SQM 19.06), a poor urban/suburban sky for astronomy.

Is Cairns good for stargazing?

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

Is Cairns good for astrophotography?

Broadband deep-sky imaging is heavily compromised from Cairns and a Bortle 4 or darker site is strongly recommended. Narrowband imaging of bright emission nebulae remains viable from Cairns with appropriate Ha or OIII filters.

What can you observe from Cairns?

Primary targets from Cairns include Moon, planets, bright double stars, bright open clusters, narrowband imaging with careful processing. Targets such as visual deep-sky observing, broadband galaxies, reflection nebulae are not realistic from this sky.

Where are darker skies near Cairns?

The closest meaningfully darker mapped site is Yarrabah, Queensland, about 13 km south east of Cairns, reaching Bortle 4.

When is the sky darkest in Cairns?

The sky over Cairns is darkest around June, July.

Is light pollution in Cairns getting better or worse?

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

• Yarrabah, Queensland

  Direction

  SE

  Distance (km)

  12.5

  SQM

  21.11

  Bortle

  4

• Bellenden Ker, Queensland

  Direction

  SSE

  Distance (km)

  44.6

  SQM

  21.35

  Bortle

  3

• Trinity Beach, Queensland

  Direction

  NNW

  Distance (km)

  15.6

  SQM

  20.00

  Bortle

  6