Growing Degree Days & Development Predictor

Temperature Unit

Mode Selection

1. Daily GDD Calculator

Enter the daily maximum and minimum temperatures and the base (or threshold) temperature. Base Temp (°C for Plants):

2. GDD Accumulation

Add your daily GDD entry along with the date to build an accumulation record.
You can also set a new biofix (reset) date below.

Total Accumulated GDD: 0

3. Crop Stage Predictor

Select a crop and enter your accumulated GDD to predict the growth stage.

4. Insect Development Predictor

For insect pests, enter your accumulated insect GDD and the target value to check if the target stage has been reached.

5. GDD Accumulation Chart

6. How to Use This Tool

Daily Calculator: Enter your day’s maximum and minimum temperatures and the base (or threshold) temperature. The app calculates GDD using both a simple averaging method and the Baskerville‐Emin method (which is more accurate when the minimum is below the base). The result is also converted into degree hours (×24).

Accumulation: Record daily GDD values along with dates to track cumulative heat accumulation. Use the Biofix Reset to start a new accumulation period.

Crop Stage Predictor: Select a crop and input your total accumulated GDD. The app compares your value to published threshold ranges (converted to your selected unit) and predicts the current growth stage.

Insect Development Predictor: For insect management, enter your accumulated insect GDD and target threshold to determine if the pest has reached a key development stage.

Note: Weather conditions and microclimates affect development. Use these predictions as guidelines and validate with field observations.

Show Detailed Background