Thornthwaite "Climatic Water Budget Analysis" is rational, systematic and quantitative, based on measured data. Unlike Köppen which attempts to use vegetation to predict large general climate areas, Thornthwaite uses temperature, precipitation, latitude, day length and soil water-holding capacity for an objective perspective of climate. Model enhancements include net primary productivity in grams per square meter per year, continentality (continental vs. oceanic influence), aspect, an Index of Moisture that accounts for precipitation (income), potential and actual evapotranspiration (spending), soil water-holding capacity (storage or withdrawal), indices of moisture in arid and humid climates. While Köppen lumps mountains into "Highlands", Thornthwaite reflects objective conditions - over a 30-year period. Climate constraints (maximums, minimums, ranges) are comparable world wide. Agriculture, urban residents, water, soil and ecosystem managers find Thornthwaite logical, rational and useful (vs. Köppen, a "memorized" system of map areas).

Historical perspectives of Thornthwaite's time and teaching in Oklahoma, working with Birdseye, doing regional geography in Kentucky, heading the Soil Conservation Service, and applying the tools of weather and climate worldwide make his life and biography long-term valuable. Understand Thornthwaite and you realize just how much "fluff" and spin current Natl Weather Service and media weather-climate reports are. This biography is defensible, robust, rational and reveals hard work and a fresh perspective.