Shanghai sits on the vast Yangtze River delta on Chinaâs east coast, around half way between Hong Kong and Beijing. With a massive 20 million inhabitants, it is large city and one of the worldâs largest metropolises. Shanghai has a humid subtropical climate marked by four distinct seasons. Climate is strongly influenced by the Asiatic monsoon winds and the cityâs coastal position on the East China Sea. Temperatures vary from the mid 30s in summer to below 0°C in winter. The weather is pretty good year round, although summer can get a little hot and muggy for some and winter is pretty harsh. On balance, autumn enjoys the best weather of the year.
Summer
This is the hottest and wettest time of year in Shanghai. In June the average temperature climbs to 24°C with highs averaging at 27°C. July and August are the hottest months of the year when the average temperature reaches 27°C; daily highs climb to 32°C and beyond - even up to 40°C - and it doesnât drop much below 25°C at night. From September it starts to cool, but it is still a very hot month.
The summer heat is often punctuated by heavy rains, usually falling in afternoon thunderstorms that are heavy but short-lived. The heat and precipitation make summer very humid and the overall effect is oppressive. The wettest months are June and September with over 150mm average rainfall each. July and August average around 130mm. Summer thunderstorms can sometimes bring very heavy rain to Shanghai and there is a risk of flooding in certain parts of the city.
Shanghai can occasionally be hit by typhoons, although direct hits are rare. These intense storms form in the northwest Pacific Ocean and if they make land they can cause enormous damage. Typhoon season runs from May to November. September 2007 saw Shanghai come in the path of a very strong typhoon that led to 1.6million people being evacuated from the city and its surrounds. The region is very well prepared, however, and often it is just a case of closing the doors and windows and sheltering indoors for 24 hours.
Autumn
This is one of the best times to visit Shanghai. Temperatures are very comfortable and rainfall is low. Late September and early October are especially good times; the summer rains have died down and temperatures range between the mid teens and mid 20s. October averages just 60mm rainfall, a sharp decline from the 160mm that is the norm for September. November rainfall is even less around 50mm and itâs another great month, though it sees the first cool temperatures with night time lows dropping to single figures. Daily highs are still in the high teens, however.
Winter
Winter can be cold in Shanghai, although its coastal position does mean temperatures donât drop as low as in inland areas. January is the coldest month of the year, with an average of 4°C, ranging from lows of 0°C to highs of 8°C. December and January are only a little warmer, averaging around 6°C or 7°C. While temperatures below zero are rare they can occur during particularly cold snaps, and snow can even fall. Winter is the driest time of the year in Shanghai, and the abundance of sunshine makes it very pretty. However, strong winds can make it feel much cooler than the recorded temperature.
Spring
Spring is another good time to visit Shanghai. Temperatures are a little cooler than autumn and rain a little more frequent but the weather is generally very pleasant. March is still cool, with an average of 9°C, but temperatures quickly increase throughout spring with May averaging 20°C. Rainfall quickly increases too, however, with April and May seeing the first of the heavy rains and averaging over 100mm.