Fontana 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

Fontana: The Practical Verdict

Fontana in California is a small city that faces substantial issues with light pollution. This results in a severe urban sky, heavily limiting astronomical observation. The primary limiting factor is the high level of light pollution, giving the area a Bortle 9 classification where the Milky Way is not visible.

From Fontana, the most viable celestial targets are the Moon, planets, and bright stars. Double stars and solar system events are achievable targets. It's possible to observe the brightest nebulae and open clusters with care, but visual deep-sky observations and most meteor showers are out of reach.

For those keen on deeper exploration, Ventura County, roughly 215 km to the west-south-west, offers a significant improvement with Bortle 2 skies, making it worth the effort for committed deep-sky observing.

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

Ventura County, California sits about 215 km west south west and reaches Bortle 2, roughly 37x darker.

Good dark window

Fontana'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 Fontana?

No. Fontana 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 Fontana?

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

Is Fontana good for stargazing?

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

Is Fontana good for astrophotography?

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

What can you observe from Fontana?

Primary targets from Fontana 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 Fontana?

The closest meaningfully darker mapped site is Riverside County, California, about 63 km south of Fontana, reaching Bortle 7.

When is the sky darkest in Fontana?

The sky over Fontana is darkest around January, December.

Is light pollution in Fontana getting better or worse?

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

• Riverside County, California

  Direction

  S

  Distance (km)

  62.9

  SQM

  19.41

  Bortle

  7

• Cottonwood Road, California

  Direction

  SW

  Distance (km)

  122.5

  SQM

  20.88

  Bortle

  4

• Lincoln Crest, California

  Direction

  WNW

  Distance (km)

  98.9

  SQM

  20.11

  Bortle

  6

• China Canyon Road, California

  Direction

  SW

  Distance (km)

  165

  SQM

  21.65

  Bortle

  3

• Ventura County, California

  Direction

  WSW

  Distance (km)

  215

  SQM

  21.72

  Bortle

  2

• Cementerio, California

  Direction

  W

  Distance (km)

  271.9

  SQM

  21.69

  Bortle

  3