In the afternoon we have seen pretty ice crystal halos. They may have been "sun dogs" ("phantom suns"), but I'm not certain.
These optical phenomena are caused by the refraction of light from ice crystals drifting in the air.
The crystals are called "diamond dust", and never was a name more appropriate... Here a close-up, with enhanced colors. Pretty, aren't they!
Sun dogs typically appear in pairs, always at the same height as the sun. The red-coloured side is the one towards the sun, as you can see in the photos.