Guildford Stargazing & Astronomy Report

Key Sky Quality Metrics

SQM (mag/arcsec²)

19.58

Bortle class

Class 7 (Class 7)

Darkness Quotient

41%

Dataset

July 2026

Suburban/urban transition

Guildford: The Practical Verdict

Guildford, in the county of Surrey, is a small city with a suburban character. Astronomically speaking, the skies over Guildford are rated as poor urban/suburban, with a Bortle class 7 level of light pollution. This means that serious astronomical observing is greatly challenged by the brightness, and the Milky Way is generally not visible.

In these conditions, the most practical targets are the Moon, planets, and bright open clusters, while visual deep-sky views are effectively off the table. Bright double stars can also be worthwhile, and narrowband imaging is possible but requires effort in processing. Avoid faint meteors and broader deep-sky photography.

For a modest improvement, the nearby village of Tillington, around 30 km south, offers somewhat darker skies. While it's only a Bortle 5 and not dramatically darker, it can provide a slightly improved experience if conditions in Guildford are overwhelmingly bright.

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

Limited nearby upgrade

Tillington is the strongest nearby option but remains Bortle 5; the improvement is real but modest.

Moderate dark window

Guildford'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 Guildford?

No. Guildford is a Bortle Class 7 sky with SQM 19.58, 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 Guildford?

Guildford is Bortle Class 7 (SQM 19.58), a poor urban/suburban sky for astronomy.

Is Guildford good for stargazing?

Not for serious deep-sky observing. Guildford 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 Guildford good for astrophotography?

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

What can you observe from Guildford?

Primary targets from Guildford 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 Guildford?

The closest meaningfully darker mapped site is Tillington, about 28 km south of Guildford, reaching Bortle 5.

When is the sky darkest in Guildford?

The sky over Guildford is darkest around January, December. Significant summer limitation: around 56 nights per year have no true astronomical darkness.

Is light pollution in Guildford getting better or worse?

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

• Tillington

  Direction

  S

  Distance (km)

  28

  SQM

  20.78

  Bortle

  5

• Clanfield

  Direction

  SW

  Distance (km)

  44.3

  SQM

  20.64

  Bortle

  5

• Lamberhurst

  Direction

  ESE

  Distance (km)

  67.6

  SQM

  20.61

  Bortle

  5