Fontana Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

17.78

Bortle class

Class 9 (Class 9)

Darkness Quotient

21%

Dataset

April 2026

Inner city sky

Fontana: The Practical Verdict

Fontana, situated in California, presents challenging conditions for stargazing due to its severe urban light pollution. The sky quality, categorised as Bortle 9, makes dark-sky observing nearly impossible, with the Milky Way completely invisible.

Only the brightest targets such as the Moon, planets, and binary stars are visible through the light domes. Some deep-sky observing of globular clusters or significant nebulae is marginally achievable with narrowband filters but yields limited success.

For meaningful improvement, a relocation to Ventura County, California, about 215 km west south west, is highly recommended. This area offers a vastly darker sky classified as Bortle 2. Serious observers should consider this option to maximise their experience.

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 38x 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 17.78, 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 17.78), 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 Lake Los Angeles, California, about 75 km north west of Fontana, reaching Bortle 5.

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?

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

• Lake Los Angeles, California

  Direction

  NW

  Distance (km)

  75

  SQM

  20.34

  Bortle

  5

• Cottonwood Road, California

  Direction

  SW

  Distance (km)

  122.5

  SQM

  20.88

  Bortle

  4

• 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

• Slab City, California

  Direction

  ESE

  Distance (km)

  191

  SQM

  20.75

  Bortle

  5

• Cementerio, California

  Direction

  W

  Distance (km)

  271.9

  SQM

  21.69

  Bortle

  3