This happens when it is very cold and foggy. No fun to take walks because the cold creeps into your coat, but then everything looks like a fairytale landscape, or like those strange infrared photos where the sky is black and trees are white. Everything is covered by tiny ice crystals. People who walk through this frozen fog eventually seem to get grey hair as even their hair gets covered by ice crystals.
I took a very short walk just near our house - enough ice covered tree beauty to find here.