Drought Index Calculator
Estimate a Palmer Drought Severity Index (PDSI) category from temperature, precipitation, and soil moisture data. Includes water balance analysis and impact assessment.
Inputs
Results
PDSI Estimate
-3.1
Drought Category
Severe Drought
How to Use This Calculator
- Enter Average Temperature (°C or °F) and Total Precipitation for the period being assessed.
- Input Normal Precipitation and Normal Temperature for the same period at the same location (long-term averages).
- Set Soil Moisture Capacity (mm) — the water-holding capacity of the local soil type.
- Review PDSI Estimate and Drought Category: 0 to -1 = abnormally dry, -2 = moderate, -3 = severe, -4+ = extreme drought.
- Use Precip Departure and Precip Ratio to contextualize how far current conditions deviate from normal.
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