1, approx. limits of Trade Wind belts, April-September; 2, same in October-March; 3, approx. trend of main currents; 4, of main drifts; 5, encloses area dominated by Southeast Asian monsoons; 6, areas of high typhoon risk, especially July-October; 7, belt of calms and light airs (Doldrums). Figures indicate frequency of prevalent wind in total observations, excluding calms. Central meridian 165°W.

Compiled from Fiziko-Geograficheskiy Atlas Mira (Moscow 1964), Plates 40–1; British Admiralty Charts 5215, 5216. Base map by courtesy of American Geographical Society, New York.