Will the weather make up it's mind?

I had a great training run today. It was my 11th training run, 4 miles today, 13 miles for the week, and 44 miles overall. Yesterday, when I started my run, I had to take ice off the car window as I opened the door to get my IPOD out. This afternoon, it was 68 degrees. I thoroughly enjoyed the beautiful weather today, but it's hard to believe i went from a 29 degree run to a 68 degree run that quickly.
While I did enjoy being outside today, I was fighting soreness from the big hills I ran yesterday. I took it pretty easy for the first three miles, then ran the last mile pretty hard.