Today's high temperature of ~ +5C will occur early this evening, approximately 8:00 PM, . By 10 PM, the temperature is predicted to have dropped to -2C, -5 by midnight, -10 by morning. This is accompanied by high winds. Bare surfaces may dry up before the freeze but any accumulation of puddles will freeze up and snow banks will become rock solid.
Tuesday will see an Alberta clipper coming through, dropping approximately 5cm of snow (map courtesy of Weatherbell)