Isn't it also not "hot and sunny" in the evening? Couldn't you run right before sundown, or in the dark with reflectors on streets with lights?

I am just asking because I had the same problem, until I realized that I just liked the idea of working out in the morning, not actually working out in the morning. I wanted to be one of those people who works out at the crack of dawn. By accepting that I am just not one of those people, and working out at lunch and in the evening, I am working out a lot more than when I kept telling myself that "tomorrow I will get up at 5 to workout."

Also, telling yourself you are just going to run for ten or fifteen minutes can get you over the akrasia hump. And running a mile or two is better than none.