Standardized Drought Index Visualization Tool

Posted on: 5/28/2025 - Updated on: 6/19/2025

Posted by

CAKE Team

Overview

The Standardized Drought Index Visualization Tool (SDI Viz Tool) was developed to be able to quickly generate and customize multiscale Standardized Precipitation Index (SPI) and Standardized Precipitation Evapotranspiration Index (SPEI) plots. These plots portray all SPI and SPEI timescales, allowing for the visualization of both short and long-term droughts all at once and through time. More information on the SPI and SPEI can be found at the WestWide Drought Tracker.

The data used in the creation of the plots is the NOAA U.S. Climate Divisional Dataset (nClimDiv). This dataset is updated through the end of the previous month, usually by the 10th of the current month. Maps of the climate divisions and special regions can be found here.

The SPI and SPEI values were calculated on the full period of record using the R SPEI package. SDI Viz Tool code can be found at https://github.com/mcrimmins/SDIVizTool.

View Tool

Managing Organizations

Climate Adaptation Partnerships (CAP) Network

The Climate Adaptation Partnerships (CAP) network, formerly known as the Regional Integrated Sciences and Assessments (RISA) Program, comprises regional teams who conduct collaborative research on weather and climate-related issues of concern to decision makers and community planners at state and local levels. CAP is funded by the National Oceanic and Atmospheric Administration’s Climate Program Office.

University of Arizona

As a public research university serving the diverse citizens of Arizona and beyond, the mission of the University of Arizona is to provide a comprehensive, high-quality education that engages our students in discovery through research and broad-based scholarship. We aim to empower our graduates to be leaders in solving complex societal problems. Whether in teaching, research, outreach or student engagement, access and quality are the defining attributes of the University of Arizona’s mission.