VineTrack

GDD STUDY - CALCULATOR

HP-GDD Calculator

Calculate Raw GDD and Hambrook Pressure-Adjusted Growing Degree Days (HP-GDD) for any Australian location and completed Oct-Apr season, using SILO daily climate data and the published model settings.

Research and HP-GDD framework: Jonathan Hambrook

LOCATION & SEASON

Australia only: latitude -44 to -10, longitude 112 to 154.

Complete seasons only, 1976-77 to 2025-26.

Enter a location and season, then calculate.

HP-GDD is a prototype screening and interpretation index. It does not replace Raw GDD and is not a planting recommendation.

SILO is gridded, interpolated data at about 0.05 degrees (~5 km) and will not represent every vineyard microclimate.

Climate data: SILO / Queensland Government & Bureau of Meteorology, CC BY 4.0. See the Method page for full formula details.