I was recently accepted to UMich and UCSB but I’m having difficulty deciding which one I should go to. I’m planning on majoring in biology but I’m not dead set on bio as my major ((theres a possibility that I might be one of those students who switches majors soph year)). I want to have as many opportunities as I can while having a good time at the college of my choice. I really enjoy the location of UCSB and they have good academics whereas I feel like theres not much to do at Umich when it’s snowed in but they have stronger academics. Any comments or advice?
Academics are equal at undergrad level at UC and UMich, so that is not really a differentiator. UCSB now has 23% Bio majors. Lots of competition. You should only major in Bio if you are headed for med school or another health profession, or a PhD in life sciences. A BA or BS in Bio is not a particularly employable credential. You need to start thinking about what you will do when you get done. 
If you are OOS, UCSB will be extremely expensive (~$60K cost of attendance per year, on campus). If you are in state, around $34K per year on campus, still pricey, but not on par with private tuition.
Weather is a whole lot better in SB. Ann Arbor is a picturesque Midwestern college town; Santa Barbara is a beautiful coastal enclave where the billionaires are driving out the millionaires. Isla Vista is the little corner of SB where the students live, and it’s pricey. So the cost of living off campus as an upperclassman could be prohibitive.
Go where you feel at home and where you think you will do your best work. HTH. Good luck!
Probably not. According to the the university 54% of the students live off-campus. See http://admissions.sa.ucsb.edu/our-location/campus-housing
From city-data.com:
2013 Ann Arbor median rent = $1071, housing unit mean purchase price = $264K
2015 Isla Vista median rent = $1413, housing unit mean purchase price = $804.5K
Agree that with roommates etc., there is not a huge difference in monthly rent. The difference in purchase prices is substantial though, and suggests a large potential difference in cost of living. I suspect that a big reason most students live off campus is that there is not sufficient off-campus housing for all of the students.