"Re-balancing", in terms of a bike share system, refers to the process of reallocating available bikes at a given time according to the demand. Failure to meet the demand is undesirable for both the users and the bike share companies -- the former loss a mean of transportation and the later loss potential revenue. Therefore it is important to have a sense of how many people will pickup a bike at a certain time and station -- in order to redistribute excessive bikes at other locations to stations that actually have high demand. Usually re-balancing will take place manually by small trucks to move the bikes around. The analysis below will examine the bike demand in Boston, MA in August and September 2019. "Bluebikes" is a private company that operates the bike share system in the city. It employs 4-5 rebalancing vans, each with a payload of 20-25 bikes, to redistribute bicycles 24 hours a day, 7 days a week. A regression model is developed based on weather and one-hour to one-week time lag to predict the number of trips that occur at a particular time and station. Since the company is redistributing bikes every hour, one-hour time lag is appropriate, because that will allow the van-driver to know an hour beforehand on the demand of bikes at different locations. Other time lags are added to strengthen the model.