Drought is a prolonged period of abnormally low precipitation that causes water shortages in various water systems, worsened by factors like extreme heat and shifts in climate patterns. NASA's Earth observations provide valuable data for water managers to understand current conditions and make informed decisions, estimating water supply and connecting snowpack conditions to future water availability. Flash droughts can develop rapidly due to intense heat drying out soil and vegetation, with NASA satellites tracking recovery phases and providing valuable data to help communities make informed decisions. Researchers use various missions and tools to assess snow water equivalent, measure surface elevation, track changes in water bodies, estimate evapotranspiration, and monitor drought conditions, supporting water managers in making informed decisions. U.S. and French oceanographers and hydrologists have developed satellite missions to survey Earth's surface water and observe changes over time, tracking variations in groundwater and surface water to provide early warnings of droughts and floods.