US National Weather Service Upper Air Observations

The National Weather Service (NWS) Upper-air Observations Program is managed by the Office of Observations (OBS), which is part of NWS Headquarters located in Silver Spring, Maryland. Upper-air Program staff oversee the operation of 92 Radiosonde stations in North America and the Pacific Islands. It also supports the operation of 10 stations in the Caribbean. Radiosondes provide upper-air data that are essential for weather forecasts and research. OBS staff are also involved in the development, testing and implementation of new radiosonde ground systems.

Maps

NWS Weather Balloon Launch Sites
NWS Weather Balloon Alaska Launch Sites
NWS Weather Balloon Pacific Launch Sites