Growing degree-day

Growing degree days, also called growing degree units, are a heuristic tool used in phenology to measure the accumulation of heat over time. Horticulturists, gardeners and farmers use the measure to predict rates of plant and animal development, such as when a flower will bloom, an insect will emerge from dormancy, or a crop will reach maturity; the concept is credited to Reaumur, who first defined it in 1735. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/