Rainfall in IndiaThe average annual rainfall in India is about 125 cm, but it has great spatial variations.
Areas of High Rainfall: The highest rainfall occurs along the west coast, on the Western Ghats, as well as in the sub-Himalayan areas is the northeast and the hills of Meghalaya. Here the rainfall exceeds 200 cm. In some parts of Khasi and Jaintia hills, the rainfall exceeds 1,000 cm. In the Brahmaputra valley and the adjoining hills, the rainfall is less than 200 cm.
Areas of Medium Rainfall Rainfall between 100-200 cm is received in the southern parts of Gujarat, east Tamil Nadu, northeastern Peninsula covering Odisha, Jharkhand, Bihar, eastern Madhya Pradesh, northern Ganga plain along the sub-Himalayas and the Cachar Valley and Manipur.
Areas of Low Rainfall: Western Uttar Pradesh, Delhi, Haryana, Punjab, Jammu and Kashmir, eastern Rajasthan, Gujarat, and Deccan Plateau receive rainfall between 50-100 cm.
Areas of Inadequate Rainfall: Parts of the Peninsula, especially in Andhra Pradesh, Karnataka and Maharashtra, Ladakh, and most of western Rajasthan receive rainfall below 50 cm
According to the Koppen climate classification, it has seven different climatic regions:-
1. Tropical Semi-Arid
2. Sub-tropical Arid Desert
3. Sub-tropical Semi-Arid
4. Tropical Rainforest
5. Tropical Savannah
6. Sub-tropical Humid
The rainfall distribution in India is impacted by the Thar Desert and the Himalayas. Temperature and pressure changes over the Indian Ocean, the Arabian Sea, the Bay of Bengal, and the southern part of the Pacific Ocean also play a significant role in the monsoon rains over the country. Owing to the nature of monsoons, the annual rainfall is highly variable from year to year. Variability is high in the regions of low rainfall such as parts of Rajasthan, Gujarat, and the leeward side of the Western Ghats. As such, while areas of high rainfall are liable to be affected by floods, areas of low rainfall are drought-prone.