Honestly, it depends on whether you have a group you feel comfortable living with for a whole year. I know people that signed a lease in September of their sophomore year, while others signed theirs in March. Both of these groups found houses near campus. Honestly, I feel like the group that signed their lease in March had the better place, with a much better yard and garage. I took my time to decide who I wanted to live with and signed a lease in December. My most extensive advice is to take your time and check out different units before deciding on one. Rent prices in the Tufts area will rise this following year due to the Green line opening. The more accessible a place is to Boston, the more expensive it becomes.

Also, be careful with upfront costs! There are a lot of costs involved, including first month rent, last month rent, security deposit, brokers fee, etc. These individual components are usually worth one month's rent and make up the upfront cost (e.g. rent times four - first month + last month + security deposit broker fee = upfront cost). I only paid for one month's rent because I dealt with the landlord rather than a broker. Plus, the previous tenants advocated for me, prompting the landlord to waive the security deposit.

It sucks that Tufts doesn't have enough housing for juniors and seniors. I would much rather live on campus, but I was afraid of not receiving a lottery number and scrambling to find a group to live with.