I do not know the exact number of consecutive days of sub-freezing temperatures we have had in Boston recently, but it's a lot. I know it has been cold because the shape of the Charles River has changed. Near the Harvard Bridge practically the whole river is frozen . . .
. . . and you can see some geese chilling out on top of what would be the middle of the river near the Boston University Bridge.
Readers are welcome to offer bike commuter related responses to, "You know it's cold when . . . "