The city of Chengdu lies on the Chengdu Plain on the west-central edge of the Sichuan Basin, itself a deep, almost rectangular depression located on the eastern edge of the Qinghai-Tibet Plateau. Sichuan Province is characterized to the west and north by the towering Hengduan Mountains – an area that is ruggedly beautiful (bamboo forests abound), and is predominantly populated by people of Tibetan origin (many of the residents of Chengdu are also of Tibetan origin) – and to the east by the lowland area of the Sichuan Basin.
Not only are the Hengduan Mountains tall, they are also situated on an elevated crustal uplift that is the geological opposite of a depression, such as the Sichuan Basin. The weather in the mountainous region is icy cold, but clear, which contrasts almost diametrically with the neighboring mild, humid – and often overcast or outright foggy – weather of the Chengdu Plain to the east that characterizes the city of Chengdu, sometimes likened to the city of London as regards the fog and the drizzly weather. For example, Chengdu gets about 250-300 foggy, cloudy or rainy days each year.
The average winter temperature (January is the coldest month) lies between 3-8 degrees Celsius, while the average summer temperature (July being the coldest month) lies between 25-29 degrees Celsius. Average precipitation (strictly rainfall) for the Chengdu Plain is 1000 mm (about 40 in), which is almost double the amount of precipitation in the Hengduan Mountains to the west.
A summary of the weather of Chengdu might read ‘an early spring, a hot summer, a cool autumn and a warm [relatively speaking] winter’. Another old saying that describes the weather of Chengdu pokes fun at the infrequency of sunshine: ‘Shu [“Chengdu”] dogs bark at the sight of the sun’.