Rainfall in India: Pattern of Annual Rainfall, Distribution of Average Rainfall in India

Rainfall in India

The southwest monsoon and the northeast monsoon are the two major types of Rainfall in India. About 75% of Average Rainfall in India falls during the southwest monsoon, often known as the “long rains,” which span from June to September. The northeast monsoon, often known as the “brief rains,” which occur from October through December, contributes the remaining 25% of the total rainfall in India.

Southwest Monsoon

• The interaction of two air masses- the warm, humid air mass over the Indian Ocean and the colder, dry air mass over Central Asia, leads to the southwest monsoon.
• Because of this interaction, a low-pressure area forms across the Indian subcontinent, which shifts the direction of the winds from the ocean to the land.

Northeast Monsoon

• On the other hand, the northeast monsoon is brought on by the interplay of the warm Bay of Bengal air mass with the cold Siberian air mass.
• As a result, Siberia experiences a high-pressure area, which makes the winds blow from the land towards the ocean. Depending on the region, India has a wide range of rainfall.
• The eastern coast, which includes locations like Kolkata and Odisha, receives considerably less rainfall than the western coast, which includes regions like Mumbai and Kerala.
• With more than 2000 mm of precipitation annually, the northeastern states, including Assam and Meghalaya- are the wettest in the nation.

☛ Types of Rainfall

Distribution of Average Annual Rainfall in India

The Rainfall in India in 2022 was recorded at 92.5cm at the end of the monsoon season. The distribution of rainfall in India is as follows:

• Extremely Heavy Precipitation regions: These areas receive more than 400 cm of rainfall annually. West Bengal, Odisha, Assam, Meghalaya, and Arunachal Pradesh are among them.
• Very Heavy Precipitation regions: These are the areas that receive more than 250 cm of precipitation annually. These include Lakshadweep, Kerala, Tamil Nadu, and coastal Karnataka.
• Heavy Precipitation regions: These areas receive more than 200 cm of rainfall annually. These comprise Meghalaya, Arunachal Pradesh, Mizoram, Nagaland, Manipur, Tripura, Sikkim, and Assam in addition to the Andaman and Nicobar Islands.
• The Himalayan region: More than 200 cm of rainfall in this area each year. Parts of Himachal Pradesh, Uttarakhand, Sikkim, and Arunachal Pradesh are included in this.
• Desert and Semi-desert regions: These are the areas that receive less than 50 cm of rainfall annually. These include Jammu and Kashmir, Rajasthan, Gujarat, and areas of Punjab and Haryana.
• Coastal regions: These are the areas that get more than 100 cm of rain each year. These include Tamil Nadu, Kerala, Karnataka, and Andhra Pradesh.
• Inland regions: These are the areas that get more than 150 cm of rain each year. These include Madhya Pradesh, Jharkhand, Chhattisgarh, and Maharashtra.

Also, Read:

• Why Tamil Nadu Coast Receives Winter Rainfall?
• Which Wind Brings Rainfall along the Malabar Coast?

Average Rainfall in India

Every year, the Average Rainfall in India is around 125 cm of rain (890 mm). Due to the country’s very varied geography, including relief or topography, distance from the sea, etc., there is a significant variance in the amount of rainfall it receives each year.

Distribution of Rainfall in India UPSC

Aspirants preparing for the UPSC Exam should pay particular attention to the Rainfall in India chapter of geography as it is extremely important. The topic forms a significant part of the physical, economic and human Geography of India. Every year, there are 1-2 direct questions from the topic asked in the UPSC Prelims Question Papers.

Rainfall in India UPSC Questions

Question: Mumbai receives about 190 cm of rainfall during the summer monsoon period, while Pune, barely 160 km away from Mumbai, receives only 50 cm of rainfall. What could be the probable cause for this uneven distribution of rainfall in India?

1. Pune is away from the coast, and the monsoon dries up by the time they reach this place.
2. Mumbai is at the coast, while Pune is located in the ‘rain shadow’ area of the Western Ghats

Select the correct code:

1. Only 1 is true
2. Only 2 is true
3. Both 1 and 2 are true
4. Neither 1 nor 2 is true

Answer: Option B

Question: Meghalaya gets the maximum rainfall in India because:

1. It is surrounded by tall mountains.
2. It is very near to the coast.
3. Its hills are funnel-shaped, which entrap the moisture-laden winds.
4. Dense forest cover attracts moisture-laden winds.

Answer: Option C

Important Notes for UPSC
Lokmanya Bal Gangadhar Tilak	World Bank UPSC
Indian Independence Movement	Difference Between Lok Sabha and Rajya Sabha
Heads of Important Offices in India	Hunter Commission
How Much Time is Required to Prepare for UPSC	Part 21 of Indian Constitution
Role of Civil Service in a Democracy	Causes of World War 2