Today will be exactly the type of day where you might run into a man in shorts somewhere. Perhaps you'll even say to him, "Hey man, it's Dec. 12, what do you think you're doing?"
He'll tell you, "Chill, it's supposed to be mostly sunny with a high of 45 degrees, according to the National Weather Service." He will be right.
But what that man doesn't know that you now know is this: Tuesday and Wednesday will be progressively colder than today. Knowledge is power.