Most of us figured out early that winter is when it’s coldest, summer is when it’s hottest and spring and fall are in between. But contrary to the official calendar dates of winter, the coldest quarter usually begins around December 8, weeks before the official date, and ends March 9. And the official summer dates on the calendar miss out on some of our warmest months. So what gives? Video blog host Joe Hanson erases the question marks in this edition of It’s Okay to be Smart.