The relationship between the yield of fruit numbers in three types of papaya, viz lines 25 and 26 and variety Sunrise Solo, and changes in rainfall, sunshine temperature and dry spells was determined through the system approach. For each type, over a dozen monthly changes in climatic factors along various stages of floral initiation to fruit harvest could be correlated to the yields. However, through a series of recombinations of consecutive months of climatic changes and partial correlations, the climatic factors which commonly affected the three types were found to be maximum temperatures at LAG 4-4% (4-4% months before harvest) and dry spells at LAG 0-1%, which were adverse to fruit yields. Sunrise Solo fruit numbers were promoted by minimum temperatures at LAG 6-6%. In line 26, moisture at LAG 5-5% and maximum temperatures at LAG 1 promoted yields while minimum temperatures at LAG 3 had an adverse effect on yields. These effects on the development of floral into fruits are discussed.