We're a week out from the Boston Marathon now--wish I was running!! Remembering the times I ran... it was a noon start then, it's now 10 am. I remember that it would get cooler toward the end, whereas here in SoFL, it just gets warmer during your long runs, that is, if you do them in the morning.
I found this video from last year's Boston, some "sights and sounds." Enjoy!