Somehow we had some freezing rain the other day, even though the temperature was -12°C (10°F). I don't know what atmospheric condition allowed that to happen, but obviously there was warmer air up above us. Then the next night we had heavy frost. The result was some beautiful icy frost on the trees.
I drove down one of my favourite sideroads where it would be safer to stop, with neat tree shadows crossing the road.
The canopy of trees was white against the blue sky.