During October and November, the southwest monsoon winds become weaker and start retreating.
Retreating Monsoon
- This season is marked by clear skies and an increased temperature in the northern plains. The retreat of the monsoon is at a marked level. This increase in temperature is termed October heat.
- At this time, the low-pressure conditions shift to the Bay of Bengal giving rise to cyclonic depressions. These cyclonic depressions often result in the destruction of life and property generally on the eastern coast and the southern coast. Most of the rainfall of the Coromandel Coast is derived from depressions and cyclones.
Tropical Cyclones
- Tropical depressions originating in the Bay of Bengal are caused by local variation of heat and moisture. They result in tropical cyclones in November and December.
- They generally originate in the neighborhood of the Andaman and Nicobar Islands between 12°N and 17°N and travel eastwards towards the Bay of Bengal. They result in a heavy downpour and cause great loss of life and property.
October Heat
- The month of October is marked by a clear cloudless sky, high temperature, and high humidity. This is called October heat.
- The month is also a period of transition between the hot rainy season and the cold dry season.
Features of Rainfall in India
- Rainfall in India is mainly concentrated to the months of July, August and September.
- In India, the rainfall is mainly orographic in nature. The places located on the windward side receive more rainfall than the places located on the leeward side.
- Only a small amount of rainfall is received from cyclones and convectional rainfall. 4. Monsoon in India is erratic, uneven and unpredictable. While there are floods in some regions, the other regions experience drought.
Distribution of Rainfall in India
Regions receiving heavy rainfall (more than 200 cm)
- Slopes of the Western Ghats and the Western Coastal Plains
- Meghalaya Hills (Garo, Khasi and Jaintia), the southern slopes of the Eastern Himalayas, Assam, Arunachal Pradesh and West Bengal
Regions receiving moderate rainfall (100–200 cm)
- The southern parts of Tamil Nadu and the northern parts of Andhra Pradesh
- Middle Ganga Valley, some parts of the Western Ghats, Eastern Maharashtra, Madhya Pradesh and Odisha
Regions receiving low rainfall (50–100 cm)
- Parts of the Deccan plateau comprising the regions of Karnataka, Andhra Pradesh and Tamil Nadu
- Eastern Rajasthan, Punjab, Haryana and Kashmir
Regions receiving scanty rainfall (100–200 cm)
- Northern parts of Kashmir, southern Punjab and western Rajasthan
- The rain shadow regions of the Western Ghats lying in the Deccan Plateau
Also, Read 4 Seasons in India