Subhumid climate

From Glossary of Meteorology



subhumid climate

A humidity province of Thornthwaite's 1931 climate classification, defined by precipitation-effectiveness index values of 32–63, and designated letter code C.

Based on its typical vegetation, the subhumid climate is sometimes called grassland, or prairie, climate. In 1948, Thornthwaite divided this category into moist subhumid and dry subhumid climate, with moisture index values of 0 to +20 and -20 to 0, respectively. The zero value of moisture index also divides, overall, the moist climates from the dry climates. This type of climate and the semiarid climate are very susceptible to drought conditions.

Thornthwaite, C. W. 1931. The climates of North America according to a new classification. Geogr. Rev.. 21. 633–655.

Thornthwaite, C. W. 1948. An approach toward a rational classification of climate. Geogr. Rev.. 38. 55–94.


Copyright 2022 American Meteorological Society (AMS). For permission to reuse any portion of this work, please contact permissions@ametsoc.org. Any use of material in this work that is determined to be “fair use” under Section 107 of the U.S. Copyright Act (17 U.S. Code § 107) or that satisfies the conditions specified in Section 108 of the U.S.Copyright Act (17 USC § 108) does not require AMS’s permission. Republication, systematic reproduction, posting in electronic form, such as on a website or in a searchable database, or other uses of this material, except as exempted by the above statement, require written permission or a license from AMS. Additional details are provided in the AMS Copyright Policy statement.