If you go from -13 to 0, you have an increase of 13 degrees. Then if you go from 0 to 22 you have an increase of 22 degrees. 13 + 22 = 35. 3:00 am to 10:00 am is 7 hours so: 35 degrees/7 hours = 5 degrees/hour Also english is my second langauge so sorry if it's hard to understand