San Francisco Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

17.74

Bortle class

Class 9 (Class 9)

Darkness Quotient

21%

Dataset

July 2026

Inner city sky

San Francisco: The Practical Verdict

San Francisco, a major city in California, exhibits severe urban sky conditions. Light pollution is significant, making it challenging to observe anything beyond the brightest celestial objects. The Milky Way remains invisible due to high light pollution levels.

From within the city, stargazing is limited to viewing the Moon, planets, and bright stars. Double stars and solar system events might also catch your eye. However, most deep-sky objects, including galaxies and nebulae, are beyond reach unless narrowband imaging is employed with caution.

For those seeking improved observation opportunities, Bolinas to the west-north-west offers a measurable upgrade. Approximately 30 km away, it provides a Bortle 4 sky, significantly enhancing the visibility of deep-sky targets. This site represents the best nearby option for dedicated individuals willing to travel.

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

Bolinas, California sits about 30 km west north west and reaches Bortle 4, roughly 18x darker.

Good dark window

San Francisco'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 Francisco?

No. San Francisco is a Bortle Class 9 sky with SQM 17.74, 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 Francisco?

San Francisco is Bortle Class 9 (SQM 17.74), a severe urban sky for astronomy.

Is San Francisco good for stargazing?

Not for serious deep-sky observing. San Francisco 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 Francisco good for astrophotography?

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

What can you observe from San Francisco?

Primary targets from San Francisco 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 Francisco?

The closest meaningfully darker mapped site is Richmond, California, about 22 km north north east of San Francisco, reaching Bortle 7.

When is the sky darkest in San Francisco?

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

Is light pollution in San Francisco getting better or worse?

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

• Bolinas, California

  Direction

  WNW

  Distance (km)

  30

  SQM

  20.85

  Bortle

  4

• Richmond, California

  Direction

  NNE

  Distance (km)

  21.8

  SQM

  18.95

  Bortle

  7

• William Road, California

  Direction

  SSE

  Distance (km)

  47.5

  SQM

  19.22

  Bortle

  7

• Denverton, California

  Direction

  NE

  Distance (km)

  67.3

  SQM

  19.73

  Bortle

  6

• 20, California

  Direction

  NW

  Distance (km)

  108.9

  SQM

  20.73

  Bortle

  5

• Stanislaus County, California

  Direction

  ESE

  Distance (km)

  108.7

  SQM

  19.20

  Bortle

  7