Zhu Kezhen (1890 - 1974) was a Chinese scientist who became a well-known specialist in climatology, the science that deals with patterns of climate. He introduced to China the science of phenology, the study of periodic natural occurrences that are related to climate, such as animal migration. He made a detailed study of the climate changes in China over 5,000 years. Zhu Kezhen also made groundbreaking contributions to the study of floods.

Zhu Kezhen was born in Shaoxing, Zhejiang Province. In 1910, he entered the College of Agriculture of the University of Illinois. In 1913, he studied meteorology in graduate school at Harvard University.

After he received his doctor's degree in meteorology, Zhu Kezhen returned to China. He taught in several schools in Wuhan, Nanjing, Shanghai, and Tianjin.

In 1928, he joined the Academia Sinica, founding China's Institute of Meteorology, which became the Institute of Atmospheric Physics.

From 1936 to 1949, Zhu Kezhen was the president of Zhejiang University. After Mao Zedong established the People's Republic of China in 1949, Zhu Kezhen became vice president of the Chinese Academy of Sciences, a national research center for natural sciences and high technology in China. Under his direction, in 1957, the academy established an office that developed into the Institute for the History of Natural Science.

He also served in such roles as deputy chairman of the Chinese Association for Science and Technology, president of the Chinese Geographical Society, president of the Chinese Meteorological Society, director of the Department of Bioscience and Geoscience, chairman of the Integrated Investigation Committee of Natural Resources, chairman of the Translation and Publication Committee, and chairman of the Committee for the History of Natural Science.

In 1961, Zhu Kezhen was elected a member of the International Academy of the History of Science.

Zhu Kezhen died in 1974.