Classifications

Category Description Possible Impacts Palmer Drought Index CPC Soil Moisture Model (Percentiles) USGS Weekly Streamflow (Percentiles) Standardized Precipitation Index (SPI) Objective Short and Long-term Drought Indicator Blends (Percentiles)
D0 Abnormally Dry Going into drought: short-term dryness slowing planting, growth of crops or pastures. Coming out of drought: some lingering water deficits; pastures or crops not fully recovered. -1.0 to -1.9 21-30 21-30 -0.5 to -0.7 21-30
D1 Moderate Drought Some damage to crops, pastures; streams, reservoirs, or wells low, some water shortages developing or imminent; voluntary water-use restrictions requested. -2.0 to -2.9 11-20 11-20 -0.8 to -1.2 11-20
D2 Severe Drought Crop or pasture losses likely; water shortages common; water restrictions imposed. -3.0 to -3.9 6-10 6-10 -1.3 to -1.5 6-10
D3 Extreme Drought Major crop/pasture losses; widespread water shortages or restrictions. -4.0 to -4.9 3-5 3-5 -1.6 to -1.9 3-5
D4 Exceptional Drought Exceptional and widespread crop/pasture losses; shortages of water in reservoirs, streams, and wells creating water emergencies. -5.0 or less 0-2 0-2 -2.0 or less 0-2