Lets set aside law school for a few minutes. Having lived for several years in Central Wisconsin, where I would visit Chicago fairly frequently (or heading south as we would say), I can tell you with no hesitation that Chicago is not like California, especially Southern California. It is not a small thing to consider that the climate in the winter has the potential to be brutal, between the cold, wind, snow and ice. For those not acclimated, it can be an attack on the senses.
Obviously this is something that most can adapt to, but keep in mind that if you have not been through, it will be an extra item to toss onto the pile while you are going through the big adjustment of being a 1L. If you do opt to go to Chicago, may I suggest buying a very warm winter coat, set your wardrobe up for dressing in layers, by and wear wool socks. Anytime that you plan on going outside, be sure to leave yourself more time to get from place to place then your California trained brain will tell you that you need to get from point A to point B as you adapt to dealing with piles of snow, buried and/or ice covered sidewalks and parking lots, etc.
Despite the not nice weather, Chicago is an interesting city, one that I recommend that most people should see, although I find it a nicer place to be in the warmer months.