The transportation system in New York is a network of complex infrastructural systems. Recently, cycling is rapidly growing as a crucial component in transportation and social activities. The growing network of citibike is providing a great subject for researchers to study citizen’s behavior through patterns in its ridership. The idea explored in this paper is to look into the seasonal change of trip duration in citibike dataset. It is observed that the data shows a relatively low bike usage during winter months. It is presumed that many subscribers follow a pattern in trip duration, such as grocery shopping or commuting. However, it is not clear that whether there is a seasonal dynamic in such usage pattern.