What time does it get light and dark?

explained

What do "light" and "dark" actually mean?

Sunrise and sunset mark the moment the sun appears above or drops below the horizon. But it doesn't turn pitch dark right away: there's a period of twilight afterwards during which the light gradually fades.

Civil twilight: when it actually gets dark

The "fully dark by" figure above shows the end of civil twilight — the moment the sun is roughly 6 degrees below the horizon. Before that point there's usually enough light to read or cycle outside without lights; after it, you'll want a bike light or street lighting.

Why do days shorten fastest in autumn?

Around the equinoxes the earth's tilt relative to the sun means daylight changes fastest: often 3 to 4 minutes shorter each day at mid-latitudes. Around the solstices, in contrast, daylight barely shifts for days at a time. Read more about how weather changes through the seasons.

Frequently asked questions

What time does it actually get dark, not just sunset?
After sunset it stays dim for a while longer. It's only at the end of civil twilight, roughly 20 to 40 minutes after sunset depending on latitude and season, that the sky is dark enough for the first stars to appear and artificial light becomes necessary.

Why do sunrise and sunset times vary so much by location?
Latitude has the biggest effect: places closer to the poles see far more seasonal daylight swing than places near the equator. Longitude also shifts the clock time of sunrise and sunset within the same timezone.

How much shorter do the days get in autumn?
Around the equinoxes daylight changes fastest, often by 3 to 4 minutes a day at mid-latitudes. Near the solstices, daylight barely changes from one day to the next.