The summer monsoon brings heavy rains and creates a moisture-rich atmosphere, while the winter monsoon generates long periods of dry and arid conditions. The summer monsoon generally begins in April and lasts through late September, while the winter monsoon arrives in October and ends in March. Rainfall produced during the summer monsoon can be very intense; flash floods and even crop damage are not uncommon in regions subject to the monsoon's effects.
The duration and conditions associated with both monsoons depend largely on the conditions over the Indian Ocean, where they form and the presence or absence of other atmospheric conditions. Generally, the end of winter brings warm and humid air from the southwestern part of the Indian Ocean; this air makes its way towards land, eventually settling over Southeast Asia.
The summer monsoon brings rain every day. Excessive atmospheric moisture and unusually warm air can create torrential, relentless rains that may devastate crop fields and wreak havoc in riverside communities and cities.
Winter monsoons arrive in October; they are characterized by dry air and cooler temperatures, offering rain-soaked regions a welcome relief from months of endless rains. Winter monsoons are usually less powerful than summer monsoons and may bring high winds in addition to drier air.