Astronomical twilight times
When does it actually get dark? Tonight’s twilight stages for your place, and which ones matter for planets, stars and faint galaxies.
When does it get dark tonight in London?
Tonight in London, astronomical twilight ends at 20:20 and the sky stays fully dark until 05:17, about 9.0 hours. Sunset is at 18:29; bright planets and stars appear after civil twilight ends at 19:02.
Calculated for Mon, 5 Oct 2026 · London, United Kingdom
Times for London, United Kingdom
- Sunset
- 18:29
- Full darkness
- 20:20–05:179.0 hours
- Sunrise
- 07:09
- SunsetThe Sun’s upper edge goes below the horizon.
- Civil twilight endsSun 6° below the horizon. The brightest planets and stars appear.
- Nautical twilight endsSun 12° below. The horizon fades; most constellations are clear.
- Astronomical twilight endsSun 18° below. Full darkness: the best time for galaxies, nebulae and the Milky Way.
- Astronomical dawnSun back to 18° below. Faint objects start to fade.
- Nautical dawnSun 12° below. The horizon becomes visible again.
- Civil dawnSun 6° below. Only the brightest planets remain.
- Sunrise
How SkyMate knows
Twilight stages are defined by the Sun’s altitude below the horizon: civil twilight ends at 6°, nautical at 12°, astronomical at 18°. SkyMate finds the moments the Sun crosses each altitude for your place with the astronomy-engine library, including atmospheric refraction for sunset and sunrise. At high latitudes in summer some stages never happen; the page says so instead of showing a time.
Data: astronomy-engine (MIT). How visibility is calculated · Astronomy data · Sources and licences