And your photos show it! Brrrrr! Crisp and clear frosty weather = crisp and clear photos! Lovely: brick and a blue sky yet again - your secret recipe, right?
What are the white flecks on the river water???
Do I need to tell you explicitely that I like the first and last best? I do.
Those are bits of ice forming in the flowing water. I expect the current in that pool makes them move in circles and that is where the shape comes from.