Monsoon

A monsoon is a seasonal change in the direction of the prevailing, or strongest, winds of a region. 

• Monsoons cause wet and dry seasons throughout much of the tropics. 
• Monsoons are most often associated with the Indian Ocean.

Monsoons always blow from cold to warm regions. The summer monsoon and the winter monsoon determine the climate for most of India and Southeast Asia.

Summer Monsoon

The summer monsoon is associated with heavy rainfall. It usually happens between April and September. 

• As winter ends, warm, moist air from the southwest Indian Ocean blows toward countries like India, Sri Lanka, Bangladesh, and Myanmar. 
• The summer monsoon brings a humid climate and torrential rainfall to these areas.

Winter Monsoon

The Indian Oceans winter monsoon, which lasts from October to April, is less well-known than its rainy summer equivalent. 

• The dry winter monsoon blows from the northeast. These winds start in the air above Mongolia and northwestern China. 

Winter monsoons are less powerful than summer monsoons in Southeast Asia, in part because the Himalaya Mountains prevent much of the wind and moisture of the monsoons from reaching the coast. 

• The Himalayas also prevent much of the cool air from reaching places like southern India and Sri Lanka, keeping them warm all year. Winter monsoons are sometimes associated with droughts.

Not all winter monsoons are dry, however. Unlike the western part of Southeast Asia, the eastern, Pacific coast of Southeast Asia experiences its rainy season in the winter. The winter monsoon brings moist air from the South China Sea to areas like Indonesia and Malaysia.

Other Monsoons

The Asian-Australian monsoon, which includes the Indian Ocean, stretches from northern Australia to Russias Pacific coast. This huge monsoon wind system then stretches into the Indian Ocean. Finally, it reaches its end on the Indian coast of Africa.

Monsoon winds exist in other parts of the world, too. The North American monsoon happens once a year, usually in the middle of summer. 

• Warm, moist air from the Gulf of California blows northeast, while warm, moist air from the Gulf of Mexico blows northwest. 

These two winds meet over the Sierra Madre Occidental mountains in central Mexico. The monsoon brings moisture to the mountain ecosystem before continuing north to the U.S. states of Arizona, New Mexico, and Texas.

• The North American monsoon can be a natural aid to fire fighters. Summer temperatures in Arizona regularly reach more than 100 degrees Fahrenheit, making wildfires difficult to contain. 
• The North American monsoon is also the primary water source for most desert ecosystems in the region. 
• However, it can also confuse and interrupt daily life for people and businesses not used to dealing with heavy rain.

credit:-

• NGC