Growing degree days, or GDD, measure the accumulated heat that drives plant and insect development, and they predict crop maturity and pest emergence far better than the calendar does. Each day contributes a number of degree days equal to how far the average temperature rose above a base threshold below which the organism does not grow, commonly ten degrees Celsius or fifty degrees Fahrenheit for many crops. This calculator uses the standard averaging method: it takes the daily high and low, averages them, and subtracts the base temperature, clamping negatives to zero and optionally capping the high at an upper threshold as many extension services recommend. Enter the daily maximum and minimum temperature and the base, choose Celsius or Fahrenheit, and read the degree days for that day. Track a running total across the season to time planting, fertilizing and harvest. All computation runs locally in your browser for instant, private results.
Growing degree days, or GDD, measure the accumulated heat that drives plant and insect development, and they predict crop maturity and pest emergence far better than the calendar does. Each day contributes a number of degree days equal to how far the average temperature rose above a base threshold below which the organism does not grow, commonly ten degrees Celsius or fifty degrees Fahrenheit for many crops.
Yes. Growing Degree Days Calculator is completely free, with no sign-up and no usage limits.
Yes. Growing Degree Days Calculator runs in any modern web browser. There is nothing to download or install.
Yes. Growing Degree Days Calculator runs entirely on your device in your browser, so nothing you enter is uploaded to a server.