The AVSSE I Experiment and is described tabulated rawinsonde data is presented for 25-mb intervals from the surface to 25mb for the 24 stations participating in the experiment. Soundings were taken between 1200 GMT, April 27, and 1200 GMT, April 28, 1975. Brief discussions are given on the methods of data processing and accuracy. Synoptic charts prepared from the data are presented, as well as an example of contact data.