The hydrology of south Florida is ultimately influenced by both large and small scale circulations in the atmosphere and ocean. These circulations and associated anomalies can impact temporal and spatial distributions of rainfall over south Florida during both our "dry" and "wet" seasons. For example, about two thirds of annual rainfall typically occurs during the five month period from mid May to mid October. Therefore, it seems logical that any investigation of interannual rainfall variability should begin here. In fact, observed decreases in freshwater gauged flow through several major river basins in south Florida over the last thirty years have been at least partially blamed on an accompanying decrease in tropical cylcone activity. This hypothesis is investigated here along with more definitive links to El Nino/Southern Oscillation (ENSO) and biennial rainfall trends over the last eighty three years.