The Evaporative Demand Drought Index (EDDI) is an experimental drought monitoring and early warning guidance tool. It examines anomalous atmospheric evaporative demand (E0; also known as "the thirst of the atmosphere"). EDDI can offer early warning of agricultural drought, hydrologic drought, and fire-weather risk by providing near-real-time information on the emergence or persistence of anomalous evaporative demand in a region. A particular strength of EDDI is in capturing the precursor signals of water stress at weekly to monthly timescales, which makes EDDI a strong tool for preparedness for both flash droughts and ongoing droughts.