This index is a shorter-term indicator of dryness, calculated through the analysis of satellite- and model-based observations of conditions that influence drought. It was designed to provide a snapshot of anomalously dry or wet conditions over the past four weeks, and serves as an indicator of emerging or rapidly changing drought conditions. The maps are updated weekly over the continental United States and have a 1-kilometer spatial resolution.

The index is an indicator of the landscape’s short-term dryness status that combines several hydrologic and vegetation-related indicators commonly-used for drought monitoring. QuickDRI leverages the unique information provided by each of these indicators into a single index that characterizes how current conditions compare to historical average conditions on a continuous dryness scale spanning from drier to near average to wetter. The goal of QuickDRI is to serve as an alert for identifying areas of emerging and/or intensifying drought, as well as areas of improving drought conditions showing a wetter signal. Information on shorter-term dryness conditions can be used for a more timely early response to drought and the implementation of more effective drought mitigation actions.

QuickDRI is a composite index that combines:

• Station-based precipitation;
• Soil moisture;
• Evapotranspiration;
• Vegetation health; and
• Environmental landscape characteristics, such as soils, land use, land cover, and elevation.

Regression tree-based QuickDRI models are developed from the historical analysis of these variables, and then are applied weekly to assess the current dryness conditions across the continental United States.

A historical time series of weekly QuickDRI maps have been produced dating back to 2000. QuickDRI data, maps, and value-added products are freely available to the general public from the QuickDRI website, including:

• Current national- and state-level maps, available in png, pdf, and jpg formats,
• Archive of historical national and state maps,
• Archive of historical 1-kilometer gridded QuickDRI data for the continental United States,
• Historical time-series and map animations,
• Frequently Asked Questions,
• Other drought monitoring tool resources to analyze in combination with the QuickDRI maps.