GDD and Temperature

Each degree above the defined threshold would be defined as one growing degree day. For example, at a threshold of 10℃ (about 50℉) every degree rise in daily temperature adds one GDD.

Study the graph to the right. Find a partner and discuss the following:

  • At what temperature does the line begin?
  • What happens to the GDD as the temperature rises? By how much?
GDD chart

Fun Fact:

Other factors such as germination temperature and water requirements are often added to the GDD calculation.