Winter survival of pupae of the fall armyworm,Spodoplera frugiperda(J. E. Smith), was studied in relation to temperature and rainfall at 4 locations in Peninsular Florida. Moth emergence was greatest (51.0%) at Homestead, intermediate (27.5%) at Bradenton, and lowest (11.6%) at Sanford and Gainesville. The number of days required for emergence ranged from 15–35 and generally was greater for northern locations. Emergence of adults was positively correlated with mean soil temperature, and respective centigrade soil and air degree day values for emergence were 170 and 143.