Modified growing degree days (MGDD) are a refined version of growing degree days (GDD), which are used to estimate the growth and development of plants and insects during the growing season. MGDDs take into account both lower and upper temperature thresholds to provide a more accurate measure of growth potential.
This chart shows monthly modified growing degree day units, using data from the Midwestern Regional Climate Center. They use 50 and 86 degrees Fahrenheit for the base and cutoff temperatures, respectively, which are commonly used to monitor the development of corn.
Learn how to calculate growing degree days
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