When I went to bed at 11pm yesterday it was 40 degrees (F) outside according to my outdoor thermometer. When I woke up at 6am it was 44 degrees. How is it possible for the environment to heat up without the sun providing the energy to do so? This is the second time I've observed this recently too, so I felt curious enough to make a thread. I always thought the world cooled down at night and warmed up during the day because of the sun.