Using climatology to predict seasonal growing degree days
The web interface allows the user to choose the current day or any day during the growing season at a point in South Dakota (chosen from National Weather Service Cooperative Observer Stations). The application then calculates the number of potential GDDs between that date and the average freeze date, and the 25th and 75th percentile freeze dates to provide a range of dates for the first freeze. Likewise, the number of potential GDDs between the chosen day and the freeze dates is calculated for all years available in the period of record at the station. The 25th, 50th and 75th percentile of accumulated GDDs are also chosen to represent cool and warm summer. The final result is a 3 x 3 matrix of potential scenarios between summer temperature conditions and freeze dates to allow the user to determine a range of potential and likely accumulations of GDDs for the remainder of the season.