Evaporation climatology of Iowa
Class A evaporation-pan observations and évapotranspiration data generated from a soil-moisture program for com have been summarized. Evaporation-pan data provide an estimate of the atmospheric potential for evaporation. These data show that the peak rate occurs in early July, averaging from near 0.26 inch per day in east-central Iowa to 0.29 inch per day in southwestern Iowa. A gradient in the evaporation rate is consistently present across the state throughout the growing season, with higher rates in western Iowa.