Shanghai enjoys four distinct seasons, generous sunshine and abundant rainfall every year due to the pleasant northern subtropical maritime monsoon climate. Its spring and autumn are relatively short compared to the summer and winter. In 2002, the annual temperature was approximately 17.8 degrees Celsius. The city had 1,686.5 sunshine time in 2002 and received of 1,427.9 millimeters rain. The May-September flood season is divided into three rainy perods namely: the Spring Rain, the Plum Rain and the Autumn Rain during which 60% of the rain fall happens.