The climate of Shanghai is temperate, with relatively cold winters, and hot, muggy and rainy summers. Shanghai is the main Chinese city, and is located in eastern China, in the Yangtze (or Blue River) Delta.
Here are the average temperatures.
Shanghai - Average temperatures
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Min (°C)24712172226262217115
Max (°C)81014202528323228231711
Min (°F)363945546372797972635241
Max (°F)465057687782909082736352

Rainfall amounts to 1,150 millimeters (46 inches) per year; there is no real dry season, however, autumn is the least rainy season, while summer, when the rains occur mainly in the form of showers or thunderstorms, is the rainiest season. Here is the average rainfall.
Shanghai - Average precipitation
MonthJanFebMarAprMayJunJulAugSepOctNovDecYear
Prec.(mm)7560957584180145215855550451165
Prec.(in)32.43.733.37.15.78.53.32.221.845.9
Days1091211101311129788121

The winter, from December to February, is quite cold: the average January temperature is 5 °C (41 °F). There may be cold periods, with highs around 5 °C (41 °F) or below, and occasionally even snow can fall. In January 1977 the temperature dropped to -10 °C (14 °F), and in January 2016 to -7 °C (19.5 °F). In other periods instead the temperatures become mild (around 15 °C or 59 °F).

The spring, from March to May, is initially mild, and becomes gradually warmer. In May there are already some hot, summer-like days. Spring is a more unstable season than autumn.

The summer, from June to September, is hot and muggy. The heat island effect of the big city and the humidity from the sea make the heat annoying, especially in July and August. However, the breeze tempers the heat a bit. June is the rainiest month of the year. The periods of good weather can be sweltering, especially in July and August, with highs around 37/38 °C (99/100 °F) or more, and tropical nights. In August 2013, 41 °C (106 °F) were recorded, and in July 2017 40 °C (104 °F).

The autumn, in October and November, is initially mild, and gradually becomes cooler, and then quite cold at night by November. Rainfall is moderate.

Shanghai

Shanghai is not a very sunny city; however, the relatively sunniest months are July and August, and autumn is a little bit sunnier than spring.
Shanghai - Sunshine
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Hours444554666544

Near Shanghai, the sea (East China Sea), cold in winter, becomes warm enough for swimming from July to September; in June and October it is a bit cool.
Shanghai - Sea temperature
MonthJanFebMarAprMayJunJulAugSepOctNovDec
Temp (°C)1088111621252725221814
Temp (°F)504646526170778177726457

From time to time, from June to early November, typhoons, the tropical cyclones of Southeast Asia, can affect this area, though less so than in southern China. In May 2006, Typhoon Chanchu was the earliest typhoon to affect Shanghai in 80 years.

When to go


It is not easy to find the best time to visit Shanghai. As the spring is more rainy, you can choose autumn, especially from the end of September to the beginning of November, which is generally mild or pleasantly warm; it must be said that the arrival of a typhoon can not be excluded.