Gulf surges are increases in southerly wind during the warm season over the Gulf of California that are usually associated with increases in the moisture content of the lower atmosphere, decreases of lower-tropospheric temperature, and occasional rainfall episodes in the deserts of southwestern North America. Because these events have important local weather effects they have received attention over the past several decades. Most studies have described the characteristics of specific events. This talk will describe the structure and temporal evolution of 38 gulf-surge events using radiosonde observations and NCEP reanalyses data from the months of July and August during the years from 1980 to 1988. After individual surge events were identified from radiosonde time series at a site along the eastern side of the Gulf of California the surge characteristics were composited with respect to these dates. The mean evolution of the surge is then described and compared with similarly determined mean fields from the NCEP reanalyses. The main results of this study are that the surges, which have the largest temperature and humidity fluctuations in the lower troposphere, are associate with westward propagating waves that can be traced eastward to over the Gulf of Mexico, and that these waves are in turn often associated with tropical storms over the eastern Pacific Ocean.