UK Dark Sky & Astrophotography Forecast

Choose a peak or viewpoint

Snowdon - Yr Wyddfa

Forecast at the named peak, not a recommendation to climb it at night. Lower viewpoints can have different cloud and horizons.

Night beginning Saturday 26 September 2026. Times are UK local time.

Viewing conditions

Best available dark spell: 27 Sep, 04:00 BST to 05:00 BST.

Poor sky conditions

Forecasts disagree on rain or visibility, so viewing conditions could be poorer than the clearer outlook suggests.

Forecast models disagree about this spell.

A bright Moon remains above the horizon through full darkness, washing out fainter stars and meteors.

Near-full moon, about 100% illuminated.

Full darkness: 26 Sep, 21:00 BST to 27 Sep, 05:15 BST.

Moon-free darkness: none within this overnight period.

Moonrise around 26 Sep, 18:45 BST.

Moonset around 27 Sep, 07:55 BST.

Compare conditions through the night

Sky weather during fully dark periods
Time	Conditions
26 Sep, 21:00 BST to 22:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.
26 Sep, 22:00 BST to 23:00 BST	Poor sky conditions Cloud breaks may offer some views of the stars. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.
26 Sep, 23:00 BST to 27 Sep, 00:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.
27 Sep, 00:00 BST to 01:00 BST	Poor sky conditions Cloud breaks may offer some views of the stars. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.
27 Sep, 01:00 BST to 02:00 BST	Poor sky conditions Cloud breaks may offer some views of the stars. Moonlight washes out fainter stars.
27 Sep, 02:00 BST to 03:00 BST	Poor sky conditions Cloud breaks may offer some views of the stars. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.
27 Sep, 03:00 BST to 04:00 BST	Poor sky conditions Cloud breaks may offer some views of the stars. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.
27 Sep, 04:00 BST to 05:00 BST	Poor sky conditions Forecasts disagree on rain or visibility, so viewing conditions could be poorer than the clearer outlook suggests. Forecast models disagree.
27 Sep, 05:00 BST to 05:15 BST	Poor sky conditions Forecasts disagree on rain or visibility, so viewing conditions could be poorer than the clearer outlook suggests. Forecast models disagree.

Sky weather during fully dark periods
Time	Conditions
25 Sep, 21:05 BST to 22:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
25 Sep, 22:00 BST to 23:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
25 Sep, 23:00 BST to 26 Sep, 00:00 BST	Poor sky conditions Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud. Forecast models disagree.
26 Sep, 00:00 BST to 01:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
26 Sep, 01:00 BST to 02:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
26 Sep, 02:00 BST to 03:00 BST	Mixed sky conditions Mostly clear skies are forecast. Moonlight washes out fainter stars.
26 Sep, 03:00 BST to 04:00 BST	Mixed sky conditions Mostly clear skies are forecast. Moonlight washes out fainter stars.
26 Sep, 04:00 BST to 05:00 BST	Mixed sky conditions Mostly clear skies are forecast. Moonlight washes out fainter stars.
26 Sep, 05:00 BST to 05:10 BST	Mixed sky conditions Cloud breaks may offer some views of the stars. Moonlight washes out fainter stars.

Sky weather during fully dark periods
Time	Conditions
27 Sep, 21:00 BST to 22:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
27 Sep, 22:00 BST to 23:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
27 Sep, 23:00 BST to 28 Sep, 00:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
28 Sep, 00:00 BST to 01:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
28 Sep, 01:00 BST to 02:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
28 Sep, 02:00 BST to 03:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
28 Sep, 03:00 BST to 04:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
28 Sep, 04:00 BST to 05:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
28 Sep, 05:00 BST to 05:15 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.

Sky weather during fully dark periods
Time	Conditions
28 Sep, 20:55 BST to 21:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
28 Sep, 21:00 BST to 22:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
28 Sep, 22:00 BST to 23:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
28 Sep, 23:00 BST to 29 Sep, 00:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
29 Sep, 00:00 BST to 01:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
29 Sep, 01:00 BST to 02:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
29 Sep, 02:00 BST to 03:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
29 Sep, 03:00 BST to 04:00 BST	Poor sky conditions Cloud breaks may offer some views of the stars. Moonlight washes out fainter stars.
29 Sep, 04:00 BST to 05:00 BST	Poor sky conditions Mostly clear skies are forecast. Moonlight washes out fainter stars.
29 Sep, 05:00 BST to 05:15 BST	Poor sky conditions Cloud breaks may offer some views of the stars. Moonlight washes out fainter stars.

Sky weather during fully dark periods
Time	Conditions
29 Sep, 20:55 BST to 21:00 BST	Poor sky conditions Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud. Forecast models disagree.
29 Sep, 21:00 BST to 22:00 BST	Poor sky conditions Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud. Forecast models disagree.
29 Sep, 22:00 BST to 23:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.
29 Sep, 23:00 BST to 30 Sep, 00:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.
30 Sep, 00:00 BST to 01:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.
30 Sep, 01:00 BST to 02:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.
30 Sep, 02:00 BST to 03:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
30 Sep, 03:00 BST to 04:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
30 Sep, 04:00 BST to 05:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
30 Sep, 05:00 BST to 05:20 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.

Sky weather during fully dark periods
Time	Conditions
30 Sep, 20:50 BST to 21:00 BST	Poor sky conditions Clearer spells are possible, but other forecasts keep much of the sky obscured by cloud. Forecast models disagree.
30 Sep, 21:00 BST to 22:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
30 Sep, 22:00 BST to 23:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars.
30 Sep, 23:00 BST to 1 Oct, 00:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.
1 Oct, 00:00 BST to 01:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars.
1 Oct, 01:00 BST to 02:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars. Limited model coverage.
1 Oct, 02:00 BST to 03:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars. Limited model coverage.
1 Oct, 03:00 BST to 04:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars. Limited model coverage.
1 Oct, 04:00 BST to 05:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars. Limited model coverage.
1 Oct, 05:00 BST to 05:20 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars. Limited model coverage.

Sky weather during fully dark periods
Time	Conditions
1 Oct, 20:50 BST to 21:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Limited model coverage.
1 Oct, 21:00 BST to 22:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Limited model coverage.
1 Oct, 22:00 BST to 23:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Limited model coverage.
1 Oct, 23:00 BST to 2 Oct, 00:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Moonlight washes out fainter stars. Limited model coverage.
2 Oct, 00:00 BST to 01:00 BST	Poor sky conditions Cloud breaks may offer some views of the stars. Moonlight washes out fainter stars. Limited model coverage.
2 Oct, 01:00 BST to 02:00 BST	Poor sky conditions Cloud breaks may offer some views of the stars. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars. Limited model coverage.
2 Oct, 02:00 BST to 03:00 BST	Poor sky conditions Cloud breaks may offer some views of the stars. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars. Limited model coverage.
2 Oct, 03:00 BST to 04:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars. Limited model coverage.
2 Oct, 04:00 BST to 05:00 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars. Limited model coverage.
2 Oct, 05:00 BST to 05:25 BST	Poor sky conditions Cloud is likely to obscure much of the sky. Rain may interrupt viewing. Reduced visibility may obscure faint objects. Moonlight washes out fainter stars. Limited model coverage.

Updated 25 Sep 2026, 00:13 BST. Only available forecast nights are shown.

Check the full mountain weather for Snowdon - Yr Wyddfa

Dark surroundings and the terrain

Estimated darkness rank 804 of 980 assessed peaks (1 is darkest), based on surrounding artificial light in 2021. This is not a measurement of tonight’s sky.

2021 artificial-light baseline, not measured sky brightness or a Bortle class. Changes to lighting, blue-rich LEDs, terrain screening, atmospheric scattering and cloud-reflected light are not resolved. Similar ranks are not meaningfully distinct. Darkness is not a recommendation to climb a summit at night.

VIIRS nighttime lights: Earth Observation Group, Payne Institute for Public Policy, Colorado School of Mines. Reprocessed by OpenGeoHub/OpenLandMap. Cropped and ranked by Mountain Weather.

The terrain horizon has not been checked at this exact location. Nearby slopes or a lower campsite can have a very different view.

Will it be a good night for astrophotography?

Compare the sky-weather summary, moonlight and fully dark periods for your chosen location. A moon-free window is not necessarily cloud-free, and the best available spell can still be poor.

The sky-weather grade is not a measurement of astronomical seeing or a guarantee of sharp images. Artificial-light estimates and terrain context are separate where available. Check the mountain forecast for wind, rain and temperature before choosing a viewpoint.

Weather data: Open-Meteo (CC BY 4.0). Adapted by Mountain Weather.