As the previous reply suggested it is "highly unlikely" to get a 3 month lease. In fact many of the larger apartment complexes will only offer a 1 year lease when they could have offered a 6 month lease. These large apartment communities make money on people breaking their contract. If you are looking for a 3 month lease you are going to have to go the month-to-month route. You might be able to get a month-to-month in the Sunnyvale area but they will likely charge you slightly more per month.