Geographic Graphics

Abstract

The diagrammatic climate key presented here was developed in an attempt to simplify the teaching of climate classification at the secondary and college levels. The chart emphasizes four critical temperatures involved in the Koppen classification, and shows their relationships to the various climate types. It is hoped that use of this key will give students a better understanding of the role of critical temperatures such as 64.4° or 71.6°, symbols such as Aw or BSk, and the overall scheme of climate classification. The chart has been developed for the Köppen climatic classification as modified by Ackerman and Van Royen and popularized by Trewartha.¹ Because the modified Koppen system is widely used and accepted, that system—along with Fahrenheit temperatures—will be utilized in the following discussion. Figure 1 represents the working skeleton, which may be drawn upon the chalkboard, presented by use of transparent overlay, or handed out on individual laboratory exercise sheets.