Köppen climate classification
The Köppen climate classification divides climates into five main climate groups, with each group being divided based on seasonal precipitation and temperature patterns. The five main groups are "A" (tropical), "B" (dry), "C" (temperate), "D" (continental), and "E" (polar). Each group and subgroup is represented by a letter. All climates are assigned a main group (the first letter). All climates except for those in the "E" group are assigned a seasonal precipitation subgroup (the second letter). For example, "Af" indicates a tropical rainforest climate. The system assigns a temperature subgroup for all groups other than those in the "A" group, indicated by the third letter for climates in "B", "C", and "D", and the second letter for climates in "E". For example, "Cfb" indicates an oceanic climate with warm summers as indicated by the ending "b". Climates are classified based on specific criteria unique to each climate type.
Humid subtropical climate
Under the Köppen climate classification, Cfa and Cwa climates are either described as humid subtropical climates or mild temperate climates. This climate features mean temperatures in the coldest month between (or ) and and mean temperatures in the warmest month or higher. However, while some climatologists have opted to describe this climate type as a "humid subtropical climate", Köppen himself never used this term. The humid subtropical climate classification was officially created under the Trewartha Climate classification.