Degree-Days: Growing, Heating, and Cooling
Corn stalks growing in a field
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plant growth

How to Cite

Fraisse, Clyde W., and Silvana V. Paula-Moraes. 2018. “Degree-Days: Growing, Heating, and Cooling: ABE381/AE428, Rev. 4/2018”. EDIS 2018 (2). Gainesville, FL.


How much and when it rains, freezes, and thaws can make the difference between boom and bust for a year's crop. However, temperature can predict more than boom or bust. Atmospheric temperature can predict the growth rates of many plants. For this reason, growers use a concept called growing degree-days (GDD), sometimes called heat units. This 5-page document discusses growing degree-days, use of the AgroClimate website to track and forecast GDD accumulation, heating and cooling degree-days, and methods for calculating HDD, CDD, and GDD. Written by Clyde W. Fraisse and Silvana V. Paula-Moraes, and published by the UF/IFAS Department of Agricultural and Biological Engineering, revised December 2010 and April 2018.
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