The "Monsoon", from the Arabic "mauism" meaning "season", defines a wind that changes direction with the seasons. Monsoons develop as a result of changing patterns of atmospheric pressure caused by the varied heating and cooling rates of continental landmasses and oceans. The strongest and most well known monsoons are those which affect India and Southeast Asia during June to September. The summer monsoon, which blows southwesterly across the Indian Ocean, is extremely wet. The winter monsoon, in contrast, blows northeasterly and is generally dry.