Welcome to Bloomington where the phrase "How's the weather?" is a common part of conversation and is quite important to living in this area. For those of you from Indiana you understand how crazy the weather can get here. Still a few pointers go a long way.
Don't underestimate the Midwest for heat. Bloomington is far enough south to get into the high eighties and low nineties for most of summer. If its bad it may approach a hundred. What makes it even worse though is the humidity. All the water in the air makes it feel about ten degrees hotter than it actually is. Dress light and wear sunblock. There is also enough sitting water on campus to make bug populations high enough to be annoying. If you want to chill outside, think about using bug spray.
Welcome Week is going to be just as hot as summer most likely. And for a lot of people, the dorms you will be moving into are not going to be air-conditioned. If you know where you are living check out http://www.rps.indiana.edu/neighborhoods.cfml to find out if you will have air-conditioning or not. If you are without this luxury make sure to pack up some fans as you will be quite hot in your room. As the weeks progress the weather will start to cool off and the leaves will change on campus. This creates one of the most beautiful scenes possible. For the most part fall is an enjoyable season on campus.
For as hot as the summers get, the winters in Indiana are just as harsh. While snow is not always guaranteed this far south in the state, more than likely you will see some. Sometimes it snows a lot, sometimes only a little. The weather here is quite fickle. Undoubtedly there will be very cold days, into the low twenties and teens, possibly wind chills of single digits. Remember to bring warm stuff with you after Thanksgiving break. The dorms are heated and controllable.
This season is probably one of the prettiest on campus. The cold will hold on for a while, but suddenly the weather will change and it will get beautiful on campus again as the flowers start to bloom. Campus reaches its peak around this time, and it is certainly one of the most enjoyable times to be here.
It rains in Bloomington quite a lot. Especially during spring and summer months, however it happens in fall and winter also. Don't forget to bring an umbrella to campus. Walking twenty minutes in the rain is not much fun and can lead to you getting sick. Rain boots can be quite helpful since puddles are common. The Jordan River may look tiny in the summer but after heavy rains it will fill up and may create areas of flowing water across some lower paths on campus.
On the mention of rain, I should talk about storms. Bloomington sees its fair share of storms, most of which will come in packs for days at a time. Some trees and/or branches will be brought down but otherwise they are fairly routine.
Bloomington lies in Tornado Alley. There is not getting around this fact but it really isn't too much to worry about either. The tornado sirens went off once during my freshman year and a tornado never actually touched down. Campus is not a very good location for tornadoes so its unlikely you will ever see one here. Besides the fact that the stone buildings and basements make it quite a safe area to be.
If it is a bad year for snow, and multiple feet do fall from the sky, it is possible that school could be closed. Don't get your hopes up. It happened a few years ago and most likely won't happen again. However individual classes are more likely to be canceled. In case of bad weather check your e-mail before leaving. Your teacher may send out a message to cancel class. It is really disappointing to walk all the way there for nothing.
Be prepared for the worst and enjoy the best!