For some places, the transition from the cold of winter to the heat of summer is fairly quick. For others, it is a long, drawn out process. Here are three maps that graphically show the annual temperature low and high points, and the time between those two.
The first map shows the date where the normal (1981-2010) temperature reaches its lowest value in winter. If it spans more than one day they middle day is used. The second map shows the same information except for summer. The final maps shows the length of time (in days) between the coldest time of the year and the warmest.