Historical Palmer Drought Indices
Monthly maps of drought conditions in the contiguous U.S. as measured by the Palmer Drought Severity Index, Palmer Hydrological Drought Index, Palmer Modified Drought Index, and Palmer Z-Index (Palmer, 1965) are provided for January 1900—August 2020. Animations of any set of monthly maps for any period desired can be viewed by selecting the beginning and ending dates of interest.
Palmer Drought Severity Index
April 1900 - March 2015