accumulated temperature

(meteorology) A value based on the integrated product of the number of degrees that air temperature rises above a given threshold value and the number of days in the period during which this excess is maintained.

From a specific date, the length of time for which mean daily temperatures have been above, or below, a stated temperature; the total time for which temperatures varied from that standard. It is used, for example, to judge the fitness of a climate for a particular crop by showing how long temperatures are above the minimum required for that crop. See also degree day.