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UK Extremes

High Temp
14.1° C
Topcliffe
Low Temp
-4.9° C
Aviemore
Precipitation
2.2 mm
Scilly, Saint Mary'S
Wind Gust
41.6 mph
Warcop Range

Astronomy Forecast for Southampton

Cloud cover, astronomical seeing and atmospheric transparency for the next three days - the conditions that actually decide whether tonight's a good night to get the telescope out.

Forecast run issued 2026-11-05 06:00 UTC • Cached 12:14

Key: ■ Good/Clear   ■ Average/Partly Cloudy   ■ Poor/Cloudy   •   rows shaded blue are evening/overnight hours (20:00-07:00 local).

Thursday 5 November

Time Cloud Cover Seeing Transparency Stability Wind Temp Precip
09:00 94-100% (Cloudy) 1-1.25" (Average) 0.4-0.5 (Good) Stable E Moderate 8°C None
12:00 94-100% (Cloudy) 1-1.25" (Average) 0.4-0.5 (Good) Stable E Moderate 9°C None
15:00 94-100% (Cloudy) 1-1.25" (Average) 0.4-0.5 (Good) Stable E Moderate 9°C None
18:00 94-100% (Cloudy) 1.25-1.5" (Average) 0.4-0.5 (Good) Stable E Moderate 8°C None
21:00 81-94% (Cloudy) 1.25-1.5" (Average) 0.5-0.6 (Average) Stable NE Light 6°C Rain

Friday 6 November

Time Cloud Cover Seeing Transparency Stability Wind Temp Precip
00:00 81-94% (Cloudy) 1.5-2" (Poor) 0.5-0.6 (Average) Stable NE Light 5°C Rain
03:00 94-100% (Cloudy) 1.5-2" (Poor) 0.5-0.6 (Average) Stable NE Light 6°C None
06:00 94-100% (Cloudy) 1.5-2" (Poor) 0.7-0.85 (Poor) Stable NE Light 6°C Rain
09:00 44-56% (Partly Cloudy) 1-1.25" (Average) 0.7-0.85 (Poor) Stable NE Light 8°C Rain
12:00 31-44% (Partly Cloudy) 1-1.25" (Average) 0.4-0.5 (Good) Stable NE Light 10°C Rain
15:00 94-100% (Cloudy) 1-1.25" (Average) 0.4-0.5 (Good) Stable NE Light 10°C Rain
18:00 69-81% (Cloudy) 1.5-2" (Poor) 0.6-0.7 (Average) Stable NE Light 6°C Rain
21:00 6-19% (Clear) 1.5-2" (Poor) 0.6-0.7 (Average) Stable NE Light 5°C Rain

Saturday 7 November

Time Cloud Cover Seeing Transparency Stability Wind Temp Precip
00:00 6-19% (Clear) 1.5-2" (Poor) 0.6-0.7 (Average) Stable N Light 5°C Rain
03:00 19-31% (Clear) 1.5-2" (Poor) 0.5-0.6 (Average) Stable NE Light 5°C Rain
06:00 44-56% (Partly Cloudy) 1.5-2" (Poor) 0.5-0.6 (Average) Stable N Light 5°C None
09:00 19-31% (Clear) 1-1.25" (Average) 0.5-0.6 (Average) Stable N Light 6°C None
12:00 6-19% (Clear) 1-1.25" (Average) 0.4-0.5 (Good) Stable N Light 10°C None
15:00 19-31% (Clear) 1-1.25" (Average) 0.3-0.4 (Good) Slightly Unstable NW Light 10°C None
18:00 19-31% (Clear) 1.5-2" (Poor) 0.4-0.5 (Good) Stable NW Light 6°C None
21:00 19-31% (Clear) 1.5-2" (Poor) 0.4-0.5 (Good) Stable NW Light 6°C None

Sunday 8 November

Time Cloud Cover Seeing Transparency Stability Wind Temp Precip
00:00 6-19% (Clear) 1.5-2" (Poor) 0.4-0.5 (Good) Stable NW Light 6°C None
03:00 31-44% (Partly Cloudy) 1.5-2" (Poor) 0.4-0.5 (Good) Stable NW Light 6°C None
06:00 69-81% (Cloudy) 1.5-2" (Poor) 0.4-0.5 (Good) Stable NW Light 6°C None

Reading It

Cloud cover is the obvious one - no point setting up if it's a solid grey sky. But two clear nights can still look very different through a telescope, which is where the other two columns matter:

Astronomical seeing measures how steady the air is, in arcseconds - turbulence in the atmosphere is what makes stars twinkle and blurs fine detail on planets and the Moon, even under a perfectly clear sky. Smaller numbers are better (under 1" is good, over 2" means the image will visibly shimmer).

Atmospheric transparency measures how much starlight is lost to haze, thin high cloud or dust that isn't necessarily obvious to the naked eye - given in magnitudes lost per air mass. Smaller numbers mean a clearer, darker sky, which matters most for faint targets like galaxies and nebulae rather than bright ones like the Moon or planets.

Stability (the atmosphere's "lifted index") flags a raised risk of thunderstorms or sudden cloud building when marked Unstable, regardless of what the cloud forecast says right now.

See also: Sun, Earth & Moon • Night Sky Viewer • Sun Position • Meteor Shower Calendar

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