Working in conjunction with the oceanographic observational program of the International Indian Ocean Expedition in 1963 and 1964 was a group of instrumented aircraft which studied the tropical atmosphere of the Indian Ocean from 100 feet to 35 000 feet above the sea surface during both the northeast and southwest monsoons This monograph presents in atlas form cloud data from a majority of these flights covering over 750 hours of flying time and 155 000 nautical miles