The South – Western Monsoon is also known as Summer time Monsoon.
There are two main seasons included in it:
1. Rainy season
2. Autumn season
1. Rainy season: The time period of this season is from mid-June to mid September. Since, India is an agricultural country, rainy season is very important for Indian climate as well as economy. Atmospheric pressure, temperature, winds and rainfall found in this season can be described as given below:
Atmospheric pressure winds and rainfall: The last stage of summer season is responsible for the blowing of winds from sea to land. The winds that blow to the south of equator are attracted towards the low air pressure region developed in north – western India and so they cross the equator. After crossing the equator, these winds change their route according to Ferrel’s law and turn to the right and now their direction becomes south-western. That is why these winds are known by the name of South – Western Monsoon. About 90 per cent of the total rainfall in India takes place in this season.
Due to the peninsular location of India, south – western monsoon is classified into two parts:
- Arabian Sea Monsoon
- Monsoon of Bay of Bengal.
These branches are further classified into three parts.
2. Autumn Season: The time period of this season is from mid-September to December. It is also known as Monsoon Reversal Period.
The condition of air pressure, temperature and rainfall of this season is given as below:
Air pressure, winds and rainfall: There is uncertain condition of air pressure due to retreating monsoon. Air pressure seems to be contrary to summer, due to which it starts reversal of monsoon winds. The retreating monsoon causes rainfall in Tamil Nadu and coastal areas of south.