Chengdu has a monsoon-influenced humid subtropical climate (Köppen Cwa) and is largely mild and humid. It has four distinct seasons, with moderate rainfall concentrated mainly in the warmer months, and relieved from both sweltering summers and freezing winters. The Qin Mountains (Qinling) to the far north help shield the city from cold Siberian winds in the winter; because of this, the short winter is milder than in the Lower Yangtze. The 24-hour daily mean temperature in January is 5.6 °C (42.1 °F), and snow is rare but there are a few periods of frost each winter. The summer is hot and humid, but not to the extent of the “Three Furnaces” cities of Chongqing, Wuhan, and Nanjing, all which lie in the Yangtze basin. The 24-hour daily mean temperature in July and August is around 25 °C (77 °F), with afternoon highs sometimes reaching 33 °C (91 °F); sustained heat as found in much of eastern China is rare. Rainfall is common year-round but is the greatest in July and August, with very little of it in the cooler months. Chengdu also has one of the lowest annual sunshine totals nationally, with less sunshine annually than much of Northern Europe, and most days are overcast even if without rain. This is especially so in the winter months, when it is typically interminably grey and dreary, compounding the poor air quality. With monthly percent possible sunshine ranging from 16 percent in December to 38 percent in August, the city receives 1,073 hours of bright sunshine annually. Spring (March–April) tends to be sunnier and warmer in the day than autumn (October–November). The annual mean is 16.14 °C (61.1 °F), and extremes have ranged from −6.5 °C (20 °F) to 37.3 °C (99.1 °F).
The vast plain on which Chengdu is located has an elevation ranging from 450 to 720 metres (1,480 to 2,360 feet).
Northwest Chengdu is bordered by the high and steep Longmen Mountain and in the west by the Qionglai Mountains, the elevation of which exceeds 3,000 m (9,800 ft) and includes Miao Jiling (5,364 m, 17,598 ft) and Xiling Snow Mountain (5,164 m, 16,942 ft). The western mountainous area is also home to a large primitive forest with abundant biological resources and agiant panda habitat. East of Chengdu stands the low Longquan Mountain and the west bordering area of the hilly land of middle reaches of Min River, an area noted by several converging rivers. Since ancient times, Chengdu has been known as “the Abundant Land” owing to its fertile soil, favorable climate, and novel Dujiangyan Irrigation System.
Chengdu is located at the western edge of the Sichuan Basin and sits on the Chengdu Plain; the dominating terrain is plains. The prefecture ranges in latitude from 30° 05′ to 31° 26′ N, while its longitude ranges from 102° 54′ to 104° 53′ E, stretching for 192 kilometres (119 mi) from east to west and 166 km (103 mi) south to north, administering 12,390 square kilometres (4,780 sq mi) of land. Neighbouring prefectures are Deyang(NE), Ziyang (SE), Meishan (S), Ya’an (SW), and the Ngawa Tibetan and Qiang Autonomous Prefecture (N). The urban area, with an elevation of 500 m (1,600 ft), features a few rivers, three of them being the Jin, Fu, and Sha Rivers. Outside of the immediate urban area, the topography becomes more complex: to the east lies the Longquan Range (龙泉山脉) and the Penzhong Hills (盆中丘陵); to the west lie the Qionglai Mountains, which rise to 5,364 m (17,598 ft) in Dayi County. The lowest point in Chengdu Prefecture, at 378 m (1,240 ft), lies in the southeast in Jintang County.