The National Weather Service (NWS) is a U.S. federal agency within the National Oceanic and Atmospheric Administration (NOAA) that provides weather, hydrologic, oceanographic, and climate forecasts, warnings, and analyses for the protection of life and property across the United States, its territories, and adjacent waters.

It operates the world's largest civilian weather observation, forecasting, and warning network, utilizing radars, satellites, and automated surface stations to monitor atmospheric conditions.