Shanghai Weather and Climate

With a pleasant northern subtropical maritime monsoon climate, Shanghai enjoys four distinct seasons, generous sunshine and abundant rainfall. Its spring and autumn are relatively short compared with summer and winter. The average annual temperature is 18 degrees Celsius. The city has a frost-free period lasting up to 230 days a year. The average annual rainfall is 1,200 millimetres (about 50 inches). However, nearly 60% of the precipitation comes during the May-September flood season, which is divided into three rainy periods, the Spring Rains, the Plum Rains and the Autumn Rains.

The highest temperature is in July and August. For ten days or so in these two months, the temperature can reach 35 degrees centigrade. The coldest period is from the end of January to early February - usually during the Chinese Spring Festival. This awfully cold period will last for about three days but it seldom snows. From March to May, the conditions are pleasant so this is the best season for traveling. The 'Plum Rain Season' is from mid-June to early July. From late August to the first twenty days of September, the city is also susceptible to typhoons, none of which in recent years has caused considerable damage. Generally you will need a light coat and sweater in spring and short- sleeved shirts in summer. In autumn, long-sleeved shirts, sweater and coat are necessary, while sweater and overcoat are appropriate in winter.

From www.shanghai.gov.cn