Portland Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

18.14

Bortle class

Class 8 (Class 8)

Darkness Quotient

24%

Dataset

May 2026

City sky

Portland: The Practical Verdict

Portland, a major city in the United States, faces considerable difficulties for stargazing due to its urban density and high light pollution. With the poor city sky conditions, characterised by a Bortle Class 8 rating, the backdrop is too bright for serious astronomical observing from within the city limits. The primary limiting factor is light pollution, which washes out the sky to the extent that the Milky Way is not visible at all.

From Portland, the best stargazing targets are limited to the Moon, the planets, and bright stars and double stars. Solar system events might still catch the eye, but deep-sky objects are generally out of reach due to the excessive skyglow. Narrowband imaging can be attempted, though care will be needed to mitigate the bright background.

For those seeking darker skies, travelling 58 km to the north-west offers a more promising site with Bortle 4 conditions and a marked reduction in light pollution. This nearby location is well worth the drive for more serious deep-sky pursuits.

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

58 km NW sits about 58 km north west and reaches Bortle 4, roughly 14x darker.

Moderate dark window

Portland'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 Portland?

No. Portland is a Bortle Class 8 sky with SQM 18.14, 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 Portland?

Portland is Bortle Class 8 (SQM 18.14), a poor city sky for astronomy.

Is Portland good for stargazing?

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

Is Portland good for astrophotography?

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

What can you observe from Portland?

Primary targets from Portland 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 Portland?

The closest meaningfully darker mapped site is 58 km NW, about 58 km north west of Portland, reaching Bortle 4.

When is the sky darkest in Portland?

The sky over Portland is darkest around January, December.

Is light pollution in Portland getting better or worse?

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

• 58 km NW

  Direction

  NW

  Distance (km)

  57.5

  SQM

  20.97

  Bortle

  4

• 60 km WNW

  Direction

  WNW

  Distance (km)

  59.8

  SQM

  20.66

  Bortle

  5

• 92 km SW

  Direction

  SW

  Distance (km)

  92.3

  SQM

  20.89

  Bortle

  4

• 97 km ENE

  Direction

  ENE

  Distance (km)

  96.8

  SQM

  20.52

  Bortle

  5

• 175 km SSW

  Direction

  SSW

  Distance (km)

  175.2

  SQM

  21.03

  Bortle

  4

• 196 km NNW

  Direction

  NNW

  Distance (km)

  196.4

  SQM

  20.81

  Bortle

  4