Growing degrees (GDs) is defined as the number of temperature degrees above a threshold base temperature, at which point plant growth ceases. The base temperature used in the Hyslop Weather Station GDDs is set to zero degrees C (32 degrees F). Growing degree days are accumulated by adding each day’s growing degree amount, starting on January 1st of each year. The Hyslop weather station website GDD information has been used historically by cool season grass growers and other growers in the region to determine optimal timing for early spring N fertilizer applications.
