From Cabo Frio Island northward to the Búzios Peninsula, the climate is greatly influenced by cold oceanic upwelling from the Falkland Current off the coast (Martin, Flexor and Valentin 1989), which causes reduced precipitation and moderated temperatures. The mean annual rainfall is c. 800 mm and the mean annual temperature 25°C, with minimum 12°C and maximum 36°C. The soil's water balance is in deficit throughout the year, in marked contrast to most of south-eastern coastal Brazil. However, relative humidity averages over 80% due to the moisture-laden winds from the ocean.

