Halo around the sun

Solar halo seen in Indianapolis, Indiana by Jolynn Keutzer Bales. Thank you Jolynn!

Photo credit: Jolynn Keutzer Bales

Photo credit: Jolynn Keutzer Bales

Halos around the sun are a sign of thin cirrus clouds drifting high above our heads.

These clouds contain millions of tiny ice crystals. The halos you see are caused by both refraction, or splitting of light, and also by reflection, or glints of light from these ice crystals. The crystals have to be oriented and positioned just so with respect to your eye, in order for the halo to appear.

That’s why, like rainbows, halos around the sun – or moon – are personal. Everyone sees their own particular halo, made by their own particular ice crystals, which are different from the ice crystals making the halo of the person standing next to you.

Read more about sun – and moon – halos, plus see more great pics.

Eleanor Imster