According to weather.com it's currently 70 degrees in Madison. Sure, that sounds great for a beer festival, however, it's raining.
There are flash flood watches until late tonight.
Additionally, there's a tornado warning (not sure when it's going to expire).
If you are going to be up there bar hopping tonight, it's expected to rain from 8pm until 5 am.
So, for the festival, that means...
Wear clothes that you don't mind getting dirty.
Don't wear white pants, they will be muddy. Don't wear shoes that you don't want to get dirty.
The temps for tomorrow are supposed to be in the 80's during the festival. That should be nice, however, the ground will probably be wet.
Take a change of socks to wear on your ride home.
80's is still kind of warm to be standing around in all day, so try to find some shade, and drink plenty of water.
Have a great time. Be safe.
See you there, I'll be the guy who looks like me.