Since January 1969, a USAF RB-57F high altitude weather reconnaissance aircraft has carried a special NRC instrumentation system to measure and record stratospheric turbulence and horizontal temperature gradients encountered at altitudes from 40,000 to above 60,000 feet. The chief purpose of this co-operative program, named Coldscan, is to collect data on atmospheric conditions at altitudes to be flown by the supersonic transports. To date, 57 data flights have been flown, covering 82,000 nautical miles of the central and western United States, Ontario, and the Pacific Ocean south of Panama. This is the second Coldscan data report and includes a summary of the results of all 57 flights, in addition to detailed accounts of a selection of 20 events from Flights 19 through 56 that showed significant temperature gradients or light to moderate turbulence. These presentations include time histories of the recorded variables, flight tracks showing event positions, and meteorological analyses.