FREEDOM, Wis. (WFRV) – Something other than the warm sun and the cool breeze caught the attention of many Saturday afternoon. Painting the Northeast Wisconsin sky was a visual phenomenon known as a sun halo.
Sun halos may remind you of a colorless rainbow, however, whereas rainbows are seen after a good rain shower, sun halos form from ice.
According to WFRV Local 5 Chief Meteorologist Luke Sampe, sun halos are caused by ice crystals refracting sunlight at 22 degrees.
High, thin cirrus clouds, which occur at altitudes above 20,000 feet, are necessary to see a sun halo.
These high altitude cirrus clouds are made of mostly ice crystals which refract the sunlight, much like a prism showing the colors of a rainbow.
Cirrus clouds can signify warmer air and rain could be on the way.