Halos occur more frequently than rainbows.
In Europe and parts of the United States they can be seen on average twice a week . In the HALO3 simulation the sun is surrounded by a 22 halo and flanked by sun dogs. Passing through the sun dogs, and sometimes encircling the whole sky at the same altitude as the sun, is a parhelic circle. Upper and lower tangent arcs touch the 22 halo directly above and below the sun. A circumzenithal arc is high above all.