Climate change is altering the weather and streamflow patterns that framed the development of water and power systems across the West. Reclamation’s 2021 SECURE Water Act Report includes a drought-specific analysis using paleohydrology (tree rings), combined with projections of future climate conditions. The findings show that in the Western United States, the duration, severity, and frequency of drought will increase in the future. For more information see the underlying technical report: 2021 West-Wide Climate and Hydrology Assessment. 

Projections of future temperature consistently indicate increasingly warmer conditions across the West. As warming occurs, droughts are expected to become longer, resulting in greater water deficits, causing droughts to become more severe and more frequent. The dashboards show changes in temperature and precipitation projected to occur around the mid-21st century (2040 - 2069), relative to a baseline of 1970 - 1999. Under scenarios with higher greenhouse gas concentrations, increases in temperature are more severe than in scenarios with lower greenhouse gas concentrations.  

Some of the more severe, recent droughts we are seeing across the West today are consistent with what climate change projections indicate will happen in a warming climate. Notably, some of the recent droughts are worse than any drought in the paleo record of the last 350 years. Reclamation has conducted a west-wide drought analysis as part of the 2021 SECURE Water Act Report, to provide a framework for drought planning to help water managers plan ahead with adequate lead times. The dashboards allow users to see how droughts in the distant past compare to projected future droughts in terms of the changes to duration and drought severity that are projected to occur with climate change.