When Do Stars Come Out Tonight?

From sunset to full darkness

Stars do not switch on at sunset. The sky darkens in three stages of twilight, each named for how far the sun has dropped below the horizon, and more stars appear at each one.

Civil twilight (sun 0° to 6° below): the sky is still bright blue. Venus, Jupiter and the brightest stars, such as Sirius, Vega and Arcturus, can show near the end of it.

Nautical twilight (6° to 12°): the horizon fades and the familiar constellations fill in. When the sun reaches 12° below, the brighter stars are out. ClearSkys calls this stars out, and from a town or city it is close to everything the sky will show.

Astronomical twilight (12° to 18°): the last glow fades from the western sky. Once the sun is 18° below, the sky is as dark as it gets. ClearSkys calls this fully dark: the time for the faintest stars, the Milky Way and galaxies, if you are away from lights.

Why the time changes with where you are

How long twilight lasts depends on your latitude. Near the equator the sun drops almost straight down, so stars come out about 50 minutes after sunset and the sky is fully dark about 80 minutes after. In Delhi on 4 November, sunset was 17:33, stars out 18:26 and fully dark 18:54.

Further from the equator the sun sinks at a slant and twilight stretches out. In London on 5 November, sunset is 16:26, stars out 17:41 and fully dark 18:20, almost two hours after sunset.

In summer, north of about 48.5° the sun never gets 18° below the horizon, so the sky never becomes fully dark; further north still, it never even reaches stars out. That is why the times above can read "not tonight".

Why the sky does not get dark in summer →

What you will see from a city

Light pollution sets a floor under how dark your sky can get. In a city, the glow from street lights is brighter than the sky at the end of nautical twilight, so waiting for full darkness adds little: the stars you can see at stars out are most of what you will see all night. From a dark site, the hour after stars out is when the sky comes alive.

The moon matters too. A bright moon washes out faint stars whatever the time, so on nights near full moon the brighter stars and planets are the show.

How dark is your sky? The Bortle scale →

Will you actually see them tonight?

The times above are pure astronomy: they come round on schedule, cloud or no cloud. Whether you will see anything depends on the cloud, the moon and the haze. A ClearSkys forecast scores each hour of the night out of 100 and shows the best hours to look, up to seven nights ahead. Search your location or pick a city below: