A Graphical Method for Determining Thornthwaite Climate Classifications

Abstract

This paper presents procedures whereby the symbolization of Thornthwaite's climatic classification may be quickly and accurately determined by use of graphs and nomograms. Potential evapotranspiration adjusted for months and latitude of the station is accomplished graphically. Soil water storage, soil water deficiency, and soil water surplus are determined by the Thornthwaite accounting procedure and, once determined, the symbolization for the complete climatic designation of the station is obtained by further graphical means.N 1948 Thornthwaite published the results