When the immediate environment is characterized with cool temperatures and wispy clouds, the sun will often display the effect commonly referred to as a "solar halo". Moisture within the wispy clouds will crystallize under these cold temperatures and, when combined with solar light, we have refractions within the hexagonal crystals which lead to the effect depicted by a solar halo. Furthermore, as is the case with rainbows, the angle between the incident ray of solar light entering the ice crystal(s) and that redirected back to the observer (resultant ray) is known and, in the case of the solar halo, measures 22°; thus the size of the solar halo depicted below is approximately 44° is diameter. Given the large amount of sky these circles (or halos) cover, they are often missed when looking at the overhead sun.