High resolution radiosonde data from US Radiosonde Replacement System (RRS) stations are now available directly from NOAA’s National Centers for Environmental Information at ftp://ftp.ncdc.noaa.gov/pub/data/rrs-data/. Data are available in BUFR format at 1-second resolution for all US stations from the time at which each station was upgraded to the RRS up to the present (earliest data available from 2005).

Radiosonde data at 6-second resolution from US stations prior to RRS upgrade are still available from the SPARC Data Center at http://www.aparc-climate.org/data-center/data-access/us-radiosonde/.