This tool calculates growing degree days from daily or from spline interpolated monthly observations.
| | Name | Type | Identifier | Description | Constraints |
| Input | Mean Monthly Temperatures | Grid list (input) | TMEAN | Monthly (12) temperature observations. | - |
| Output | Number of Days above Base Temperature | Grid (output) | NGDD | Number of days above base temperature. | - |
| Growing Degree Days | Grid (output) | TSUM | Integral of daily temperature above base temperature. | - |
| First Growing Degree Day (*) | Grid (optional output) | FIRST | First growing degree day of the year (1-365). | - |
| Last Growing Degree Day (*) | Grid (optional output) | LAST | Last growing degree day of the year (1-365). | - |
| Options | Grid system | Grid system | PARAMETERS_GRID_SYSTEM | - | - |
| Base Temperature | Floating point | TBASE | Base temperature in degree Celsius | Default: 0.000000 |
| (*) optional |