Touring college campuses is something everyone should do before making a decision on which school to attend. There are both positives and negatives of touring a campus in the fall but the good outweighs the bad.
When I was making my college decision, climate played a big factor, so my top three schools were in the south. Touring in the fall, especially late fall, gives you a good idea what the weather will be like for the majority of the year. However, if you are seriously considering a school, you might want to tour again in the winter to see what you might encounter come spring semester.
Another reason to tour in the fall is because you get to see the campus in full swing. The fall brings football season, moderate weather, and thousands of college students to campus. In my opinion, the best way to see a campus is to spend the weekend on campus and go to a football game. When I was deciding on attending Florida State, I never attended the official tour.
My dad went to Florida State so I grew up a Seminoles fan and made many trips to Tallahassee. It was helpful to have someone who had spent four years on campus to show me what life was really like at the school, even though things may have changed since he went here.
I would highly recommend contacting a friend, student, or Alumni for a personal tour to get a better feel for what goes on at whichever school you choose to attend. Also, when a student tours in the fall, it gives them plenty of time to look around at other schools and decide which one you fit best.
The best course of action when choosing a school is to narrow schools down to a top five, tour each school, narrow down to fewer schools, tour again, and decide on a school. This is the process I went through and I am extremely happy I was thorough.