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HOME > Monitoring and Data > U.S. Climate Data & Maps > Degree Day Monitoring & Data > Growing Degree Days Explanation

A corn growing degree day (GDD) is an index used to express crop maturity. The index is computed by subtracting a base temperature of 50°F from the average of the maximum and minimum temperatures for the day. Minimum temperatures less than 50°F are set to 50, and maximum temperatures greater than 86°F are set to 86. These substitutions indicate that no appreciable growth is detected with temperatures lower than 50 or greater than 86.







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Page last modified: January 24, 2005
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