Monsoon is a seasonal change in winds and precipitation associated with differing heating of land and sea. There are three main types of monsoon: summer monsoon brings heavy rain between April and September as warm air blows from the southwest Indian Ocean toward countries like India; winter monsoon has dominant easterly winds and a strong tendency toward drought; and a dry monsoon occurs between October and April in South and Southeast Asia with rain-bearing winds from May to September and dry winds the rest. Monsoons result from differing annual temperature trends over land and water.