Astrophotography & night sky planner

0-10 sky rating for tonight, optimal moon-free window, moon phase and illumination, astronomical twilight, golden hour and blue hour with a countdown, and a layered cloud forecast for the next 7 nights. Astronomical calculations run in your browser; clouds come from the Open-Meteo model.

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Tonight
/10
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Moon

Golden hour and blue hour

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Next 7 nights

NightScoreClouds (dark window)MoonAstronomical darkness

Clouds and darkness · next 48 hours

Low, mid and high clouds stacked, together with the usable darkness curve (100 = moonless astronomical night; a high, well-lit moon reduces it).

Frequently asked questions

How does the moon phase affect astrophotography?

The moon is the biggest source of natural light pollution. With a full moon, the sky background brightens so much that nebulae and the Milky Way almost disappear. The ideal is to shoot deep sky on the days around the new moon or during the hours when the moon is below the horizon. To photograph the moon itself, however, the intermediate phases show the relief of the craters best.

What is the Bortle scale?

The Bortle scale rates the darkness of the sky from 1 (perfectly dark sky, no light pollution) to 9 (inner city centre). To see the Milky Way with the naked eye you need Bortle 4 or better. This tool forecasts clouds and moon, but you should check the light pollution of your area on a Bortle map: get at least 30-50 km away from large cities.

What is astronomical twilight?

It is the period when the sun is between 12° and 18° below the horizon. Only when the sun drops below -18° is the night completely dark and the sky reaches its top quality for deep-sky astrophotography. At Spanish latitudes, in high summer astronomical darkness can shrink to just a few hours, especially in the north of the mainland.

When are the golden hour and the blue hour?

The golden hour occurs with the sun between 6° above the horizon and 4° below: warm, soft light with long shadows, ideal for landscape and portrait. The blue hour arrives with the sun between 4° and 8° below the horizon: the sky turns a deep, even blue, perfect for urban and architecture photography. Both happen twice a day, at dawn and at dusk, and last 20 to 60 minutes depending on the season and latitude.