Changchun has a four-season, monsoon-influenced, humid continental climate (Köppen Dwa). Winters are long (lasting from November to March), cold, and windy, but dry, due to the influence of the Siberian anticyclone, with a January mean temperature of −15.1 °C (4.8 °F). Spring and fall are somewhat short transitional periods, with some precipitation, but are usually dry and windy. Summers are hot and humid, with a prevailing southeasterly wind due to the East Asian monsoon; July averages 23.1 °C (73.6 °F). Snow is usually light during the winter, and annual rainfall is heavily concentrated from June to August. With monthly percent possible sunshine ranging from 47 percent in July to 66 percent in January and February, a typical year will see around 2,617 hours of sunshine, and a frost-free period of 140 to 150 days. Extreme temperatures have ranged from −33.0 °C (−27 °F) to 35.7 °C (96 °F).
Changchun lies in the middle portion of the Northeast China Plain. Its municipality area is located at latitude 43° 05′−45° 15′ N and longitude 124° 18′−127° 02′ E. The total area of Changchun municipality is 20,571 km2 (7,943 sq mi), including metro areas of 2,583 square kilometres (997 sq mi), and a city proper area of 159 km2 (61 sq mi). The city is situated at a moderate elevation, ranging from 250 to 350 metres (820 to 1,150 ft) within its administrative region. In the eastern portion of the city, there lies a small area of low mountains. The city is also situated at the crisscross point of the third east–westward “Europe-Asia Continental Bridge”. Changchun prefecture is dotted with 222 rivers and lakes. Yitong River, a small tributary of Songhua River runs through the city proper.