degree-day

American  

[dih-gree-dey] / dɪˈgriˌdeɪ /

Or degree day

noun

Engineering.

1. one degree of departure, on a single day, of the daily mean temperature from a given standard temperature. dd

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degree day ¹ British  

noun

1. a day on which university degrees are conferred

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degree-day ² British  

noun

1. a unit used in estimating fuel requirements in heating buildings. It is equal to a fall of temperature of 1 degree below the mean outside temperature (usually taken as 18°C) for one day

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degree-day Scientific  

1. A unit of measurement equal to a difference of one degree between the mean outdoor temperature on a certain day and a reference temperature. The unit is most often used in estimating the energy needs for heating or cooling a building (for example, heating degree-days and cooling degree-days). Originally, degree-days were used to determine the relationship between temperature and plant growth. The term continues to be used in life sciences as a measure of upper- and lower-temperature limits for organisms.

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Etymology

Origin of degree-day

First recorded in 1925–1930

Example Sentences

The growers look at degree-day counts — what’s the average temperature each day, how much warmth are we getting — that will affect how fast the crop develops.

From Seattle Times • May 22, 2023