India receives most of its rainfall from the monsoons. It starts at the beginning of June and continues until the end of September. It accounts for 70 to 90 percent of India’s total annual rainfall, depending on the location of the station. So the rainy areas in India are practically the monsoon rainy areas. The following are the main rain zones according to the amount of monsoon rain received.
Very low rainfall area
The states below these zones receive a monsoon rainfall amount of between 250 and 450 mm of monsoon rain. These include the state of Rajasthan in the northwest and Tamil Nadu in the southeast. Rajasthan is practically a desert and known for extreme temperatures in summer and winter.
Tamil Nadu gets most of its rain from the southeast monsoon rather than the southwest monsoon.
Low rain fall zone
These include the states of Punjab, Haryana, Jummu and Kasmir, Gujrat, Andhara Pradesh, and Telangana. Here the precipitation is 451-800 mm. Hill stations receive more rain than flat areas.
Moderate rain zone
This includes most of India and compresses from Himachal Pradesh, Uttrakhand, Uttar Pradesh, Behar, West Bengal, Nagaland, Manipur, Tripura, Madhya Pradesh, Jharkhand, Chattisgarh, Odisha, Maharashratra and Karnataka. The monsoon rain here is 801-1500 mm. Here too hill stations like Darjeeling in West Bengal and Mahabaleshwar in Madhya Pradesh receive more rain than flat areas.
High Precipitation Zone
These include the states of Kerala, Sikkim, Assam, Arunchal Pradesh, Mizoram and Nicobar and the Andaman Islands. The rainfall figure here is between 1501-2500 mm. These areas are directly hit by monsoon winds and many of the stations in these states have a mountain range behind them, which increases the amount of monsoon rain.
Very high rainfall area
These include the states of Goa and Meghalaya and the monsoon rainfall here exceeds 2,500 mm. Meghalaya is well known for its exceptional amount of rainfall throughout the world. Cherrapunji, right in the Khasi Hills, has held the world record for the wettest place. The reason for the exceptional rainfall in Meghalaya is its geographical position. Here, both the Bay of Bengal branch and the Indian Ocean monsoon branch converge to give very heavy rains.
In short, the amount of monsoon rain in India is not equally distributed but varies greatly from state to state depending on their geographical location. In general, the eastern and southwestern states receive more rain than the northwestern states.
