Twice a day, every day of the year, weather balloons are released simultaneously from almost 900 locations worldwide! This includes 92 released by the National Weather Service in the US and its territories. The balloon flights last for around 2 hours, can drift as far as 125 miles away, and rise up to over 100,000 ft. (about 20 miles) in the atmosphere! //

A parachute, attached to the end of the balloon, allows the radiosonde to fall slowly to the ground at speeds less than 22 mph after the balloon bursts. Each radiosonde contains a mailing bag and instructions on what to do if you find one. About 20% of the 75,000 radiosondes sent up each year in the US are found and returned. //

Weather balloons are the primary source of data above the ground. They provide valuable input for computer forecast models, local data for meteorologists to make forecasts and predict storms, and data for research. Computer forecast models which use weather balloon data are used by all forecasters worldwide, from National Weather Service meteorologists to your local TV weatherman! Without this information, accurate forecasts beyond a few hours would be almost impossible!