India receives most of its rainfall from the monsoons. It starts in early June and continues up to the end of September. It accounts for 70-90 percent of India’s total annual rainfall depending upon the location of a station. So the rainfall zones in India are practically the monsoon rainfall zones. Following are the major rainfall zones according to the amount of monsoon rainfall received.
Very Low rainfall Zone
The states which lie under this zones receive monsoon rain amount between 250-450 mm of rainfall from the monsoon.These includes the state of Rajasthan in the North West and Tamil Nadu in the South East. Rajasthan is practically a desert and known for extreme temperatures in summer and winter.
Tamil Nadu gets most of its rain from South East monsoon instead of the south west monsoon.
Low Rain Fall Zone
These includes the states of Punjab, Haryana, Jummu and Kasmir, Gujrat, Andhara Pradesh and Telangana. Here the rainfall is between 451-800 mm. The hill stations receive more rain than the plain areas.
Moderate Rainfall Zone
This includes most of India and comprises of Himachal Pradesh, Uttrakhand, Uttar Pradesh, Behar, West Bengal, Nagaland, Manipur, Tripura, Madhya Pradesh, Jharkhand, Chattisgarh, Odisha, Maharashratra and Karnataka. The monsoon rainfall here is 801-1500 mm. Here also the hill stations like Darjeeling in West Bengal and Mahabaleshwar in Madhya Pradesh receive more rain than that of plain areas.
High Rainfall Zone
These includes states of Kerala, Sikkim, Assam, Arunchal Pradesh, Mizoram and Nicobar & Andaman Islands. The rainfall figure here is between 1501-2500 mm. These areas are directly hit by the monsoon winds and many of the stations in these states have a mountain range behind so it enhances the amount of monsoon rainfall.
Very High Rainfall Zone
These includes states of Goa and Meghalaya and the monsoon rainfall here exceeds 2500 mm. Meghalaya is well known for its exceptional amount of rainfall throughout the world. Cherrapunji, right in the Khassi Hills has had held the world record for the wettest place. The reason for the exceptional rainfall in Meghalaya is its geographical position. Here both Bay of Bengal branch and Indian Ocean branch of monsoon converge to give very heavy rainfall.
In short the amount monsoon rainfall in India is not equally distributed but varies greatly from state to state depending on its geographical location. Generally the eastern and south-western states get more rainfall than the North western states.