degree days



  • a system of measuring the amount of heat received from the sun during a growing season in a particular region. This is then used to help identify the suitability of the region for a particular type of grape and wine production. The units of heat from the sun are measured in ‘degree days’ by obtaining the raw monthly average temperature in degrees Celsius less 10 and multiplying the result by the number of days in that month, then adding together the sums for all seven months of the growing season. On the Fahrenheit scale, 50º is the equivalent starting temperature.