A Gorgeous Summertime Halo!

There was beautiful halo with rainbow colors sitting over the University of Utah campus at noon today.

I believe this is either a circumhorizon arc or an infralateral arc, which form only when the sun is high in the sky (higher than 58º).  As a result, these types of arcs form only near noon from about April to early September at our latitude.  In this instance, I suspect it was an infralateral arc because it curved up slightly from the horizon.  More info at Atmospheric Optics.