I did this one last year. I did the 100k version rather than the 100 mile. They have a cut off time and I missed it by about 15 minutes so I had to do the 100k. It was warm (low 80s), light rain at times, and it was one of the best supported rides I've done. Be sure to check out the profile map to have an idea of the elevation. One of the things that impressed me most was the Chattanooga Police. They stopped traffic at every intersection within the city limits for the cyclists as we left out and as we returned. I would definitely recommend this ride.