Ça caille à Saint-Aignan ce matin. It's colder than a well-digger's elbow. That's called "a duck's cold" in French — il fait un froid de canard. Freezing cold. That's because when wild ducks fly over, headed south, it's often often during cold spells. Ponds freeze over and the ducks are forced to move on to new feeding areas. And it might also have to do with how cold duck hunters get in winter as they wait in their blinds for some ducks to shoot at.
The dictionary gives "cold as charity" — that must be a British expression. In America we talk about witches' unmentionable parts and things you find on brass monkeys. Un froid sibérien, autrement dit — un froid de loup. When it gets and stays so cold that the wolves have to come out of hiding to find food.
So — "How cold is it?" I don't have a Johnny Carson answer to that. But the thermometer says it's -6ºC this morning. That's about +21ºF. And that's cold for Saint-Aignan. Though I hear stories about the great cold wave of the early 1980s, when the temperature went down as low as minus 20ºC — minus 4ºF — and people couldn't cut wood because all the tree trunks froze solid. That cold spell lasted for a month, they say.
So what does « ça caille » mean? That's where this post started. It means "to curdle, to clabber, to clot." As milk or cream or blood does, or as water does when temperatures drop below freezing. Or body parts, as in « on va se les cailler ». You choose the parts that you think are going to freeze off. Toes. Fingers. Ears. Buns. Any other ideas?