Clear Weather Icon

Icon
The icon is a (blue) crescent moon without any clouds. It was created using Ibis Paint X on an HP Chromebook, on December 4, 2020 at 10:32 PM CST.

Meteorology
Fair weather at night is 0 to 12% cloud cover when the sun is not up, despite what most weather icons look like, the moon does not have to be up for fair weather at night, the moon just symbolizes it.