c3p

Drought Indexes

Reading this chart info-icon

PDSI PHDI PMDI SPI 1 SPI 2 SPI 3 SPI 6 SPI 9 SPI 12 SPI 24 ZNDX

heat map showing drought indexes for NC by climate zone

Data Source: NOAA’s National Centers for Environmental Information (NCEI)

PDSI PHDI PMDI SPI 1 SPI 2 SPI 3 SPI 6 SPI 9 SPI 12 SPI 24 ZNDX

heat map showing drought indexes for SC by climate zone

Data Source: NOAA’s National Centers for Environmental Information (NCEI)

Reading a Heat Map

This chart shows a specified drought measure for each month from 1895 onward. Each row represents a single year; each column a single month, January through December from left to right. These charts help to identify unusually wet or dry periods in history. See the glossary for additional information on each drought measure.