Growing Degree Days
Accumulated growing degree days from a daily Tmax/Tmin series, a crop base temperature, and an optional upper cutoff, by the standard or modified method.
Formula and source
GDD = ((min(Tmax,cutoff) + Tmin_adj)/2) - base, floored at 0. The modified method caps Tmax at the cutoff and floors Tmin at the base before averaging.
Per the USDA / NWS growing-degree-day method and McMaster & Wilhelm (1997), 'Growing degree-days: one equation, two interpretations,' Agric. & Forest Meteorology 87, by name.
Audience
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