A diagram that shows civil, nautical and astronomical twilight. Only when the sun has sunk 18° below the horizon at night, is it completely dark.
The days are long here in the north, and the twilight lingers.
It takes until midnight before the sky is completely dark.
Looking west to the Space Needle from 14th Avenue on Capitol Hill at 9.58 pm last night, during nautical twilight (see below). Civil Twilight is from 9:10 pm to 9:50 pm Nautical Twilight is from 9:50 pm to 10:46 pm Astronomical Twilight is from 10:46 pm to 12:00 am
