Physical map of Sichuan

Physically Sichuan consists of two very distinct parts. The eastern part of the province is mostly within the fertile Sichuan basin (which is shared by Sichuan with Chongqing Municipality). The western Sichuan consists of the numerous mountain ranges forming the easternmost part of the Qinghai-Tibet Plateau, which are known generically as Hengduan Mountains. One of these ranges, Daxue Mountains, contains the highest point of the province Gongga Shan, at 7,556 m above sea level. The mountains are formed by the collision of the Tibetan Plateau with the Yangtze Plate. Faults here include the Longmenshan Fault which ruptured during the 2008 Sichuan earthquake. Other mountain ranges surround the Sichuan Basin from north, east, and south. Among them are the Daba Mountains, in the province's northeast.

The Yangtze River and its tributaries flows through the mountains of western Sichuan and the Sichuan Basin; thus, the province is upstream of the great cities that stand along the Yangtze River further to the east, such as Chongqing, Wuhan, Nanjing and Shanghai. One of the major tributaries of the Yangtze within the province is the Min River of central Sichuan, which joins the Yangtze at Yibin. Sichuan's main rivers, as Sichuan means literally, are Jialing Jiang, Tuo Jiang, Yalong Jiang, and Jinsha Jiang.

Due to great differences in terrain, the climate of the province is highly variable. In general it has strong monsoonal influences, with rainfall heavily concentrated in the summer. Under the Köppen climate classification, the Sichuan Basin (including Chengdu) in the eastern half of the province experiences a humid subtropical climate (Köppen Cwa or Cfa), with long, hot, wet summers and short, mild to cool, dry and cloudy winters. Consequently, it has China's lowest sunshine totals. The western region has mountainous areas producing a cooler but sunnier climate. Having cool to very cold winters and mild summers, temperatures generally decrease with greater elevation. However, due to high altitude and its inland location, many areas such as Garze County and Zoige County in Sichuan exhibit a subarctic climate (Köppen Dwc)- featuring extremely cold winters down to −30 °C and even cold summer nights. The region is geologically active with landslides and earthquakes. Average elevation ranges from 2,000 to 3,500 meters; average temperatures range from 0 to 15 °C. The southern part of the province, including Panzhihua and Xichang, has a sunny climate with short, very mild winters and very warm to hot summers.

Sichuan borders Qinghai to the northwest, Gansu to the north, Shaanxi to the northeast, Chongqing to the east, Guizhou to the southeast, Yunnan to the south, and the Tibet Autonomous Region to the west.