India’s climate is typically called a tropical monsoon. Tropical is a term used to describe the region between the Tropic of Cancer and the Tropic of Capricorn. Monsoon is derived from the Arabic word ‘Mausum’, which means season. The Monsoon is described as one that blows from sea to land for some time and reverses when atmospheric conditions change. 

What Causes the Monsoon?

Monsoons are caused by the shift in seasonal wind movement caused by the temperature difference between land mass and ocean. These winds move from colder to warmer areas. During summer, the land and the air above the landmass become hot. At the same time, the air above the sea is cool. Warm air is lighter than cold air, so the hot air over the landmass ascends. The cooler sea air then descends in to replace the rising air. This movement of air causes the summer monsoon winds. These winds are heavy as they carry moisture from water evaporated from the sea. The moisture in the air is then dropped over the land in heavy rainfall.

In winter, the situation becomes just the opposite. The air above the landmass cools to a temperature lower than the air above the sea. It happened because land cools faster than water. The warmer sea air rises, and the cool air above the land move towards the sea to fill the void created by warm air. This reversal shift in the movement of air is termed as the reversal or winter monsoon. As the winds coming from dry land carry little moisture, the monsoon region has a dry winter.

Indian monsoon winds blow from the southwest to the northeast—from the Indian Ocean to the Indian subcontinent. This might be the reason why some of Earth’s wettest places are in the path of the Indian Monsoon. The town of Cherrapunji and Mawsynram, in north-eastern India, has an average rainfall of more than 250 cm for July alone. 

Types of Monsoon

North-East Winter Monsoon

The north-eastern winter monsoons take place from December – March. The temperature in the Indian subcontinent is lower, creating a high-pressure zone. This high-pressure zone creates a dry air system that produces clear skies over India from November to May.

Meanwhile, a low-pressure system develops over the Indian Ocean region and northern Australia. Due to this, the winds from the subcontinent move towards the Indian Ocean.

During the winter monsoon, Australia and Southeast Asia receive large amounts of rainfall.

South-West Summer Monsoon

The Southwestern summer monsoons occur from June – September. Due to an increase in temperature, an area of intense low pressure develops over the Indian Subcontinent and Tibetian plateau. This creates winds blowing rain clouds towards India, which receives up to 10,000 mm of rain in some areas.

That’s how the South-west Monsoon brings rainfall to the Indian subcontinent.

Importance of Monsoon

Monsoons are very important to farming. It plays a pivotal role in agriculture. The Monsoon is responsible for about 70% of India’s annual rainfall. Substantial year-to-year variability in the amount and timing of the rain poses uncertainty to crop yield. The right amount of rainfall is good for crops, but failure in Monsoon may result in crop failure over large areas. Flooding from heavy monsoon rains can also damage crops.

Frequently Asked Questions on Monsoon

1. Why does India have a Monsoon type of climate?

India has a monsoon-type climate because the weather condition in India changes with a shift in monsoon winds towards the Indian subcontinent. The monsoon contributes to 70% of India’s annual rainfall.

2. How many kinds of Monsoons exist in India?

Two types of monsoons exist in India

a) The southwest monsoon. 

b)The northeast monsoon.

3. What is a retreating Monsoon?

During the months of October-November, the southwest monsoon winds become weak and start retreating from North India’s skies. During this time, rainfall is seen throughout the country. This phase of the monsoon is known as the retreating monsoon.

4. When does the monsoon arrive in India?

The southwest monsoon arrives in mainland India during May-June on the coast of Kerala. The duration of the South-west monsoon is approximately 100 days. 

5. How is the monsoon beneficial to India?

Monsoon contributes to 70% of India’s annual rainfall. It determines the yield of agriculture in that particular year. It also replenishes reservoirs and groundwater, thus resulting in better irrigation.