Weather tools

Growing Degree Day (GDD) Calculator

Calculates the accumulated Growing Degree Days (GDD) for a specific period, which is a measure of heat accumulation used to predict plant growth and development.

Before you use this tool

Use this if

  • Calculates the accumulated Growing Degree Days (GDD) for a specific period, which is a measure of heat accumulation used to predict plant growth and development.
  • You want a calculation that exposes its formula: GDD = Σ [(Daily High Temperature + Daily Low Temperature) / 2] - Base Temperature (Summed over the specified period)
  • You already have Base Temperature, Start Date, End Date values to enter.

Skip this if

  • You need an official emergency alert or life-safety instruction.
  • You need a certified professional forecast instead of a calculator estimate.
When to use or skip it

Use this if

  • Calculates the accumulated Growing Degree Days (GDD) for a specific period, which is a measure of heat accumulation used to predict plant growth and development.
  • You want a calculation that exposes its formula: GDD = Σ [(Daily High Temperature + Daily Low Temperature) / 2] - Base Temperature (Summed over the specified period)
  • You already have Base Temperature, Start Date, End Date values to enter.

Skip this if

  • You need an official emergency alert or life-safety instruction.
  • You need a certified professional forecast instead of a calculator estimate.