Surface Airways Observations (SAO) Hourly Data (1965-1981) (CDMP)
The dataset consists primarily of U.S. surface airways observations (SAO) data beginning in 1965 and extending through 1981. 

Note that a few stations have already had certain years within this 1965-81 period re-keyed as hourly. For these stations, only a subset of the period was keyed. In addition, other stations …