Monsoon winds are affected by different atmospheric conditions encountered by them on their way over the warm tropical seas. Some of the characteristics of monsoon season are:

• From early June to mid-September, the duration of the monsoon is around 100 to 120 days.
• During the time of its arrival, the moderate rainfall turns into heavy rainfall suddenly and continues constantly for several days. This is known as the 'burst of the monsoon'.
• The monsoon reaches the southern tip of the Indian peninsula generally by the first week of June. Subsequently, it proceeds into two – the Arabian Sea branch and the Bay of Bengal branch.
• Withdrawal of the monsoon is a more gradual process. By early September, the withdrawal of the monsoon begins in the northwestern states of India.

• It retreats completely from the northern half of the peninsula by mid-October.
• The withdrawal from the southern half of the peninsula is fairly rapid. By early December, the monsoon has withdrawn from the rest of the country.
• The retreat of the monsoon takes place progressively from north to south from the first week of December to the first week of January. By this time the rest of the country is already under the influence of the winter monsoon.

Effects of Monsoon:

The Indian monsoon is known for its uncertainties. The changes between dry and wet spells differ in intensity, frequency and duration. Monsoon causes floods in some parts of the country, while drought in other parts is as well. It is often irregular in its arrival and withdrawal. Therefore, it sometimes disturbs the agriculture cycle in the country.