Question

Describe the process of retreat of the summer monsoon.

Answer 1

that is that 
when Low presssure all over north becomes weaker. Temperature reduces and replaced by high pressure when monsson retreats, clear skies and temperature rises. Low Pressure conditions get transferred to the Bay of Bengal by early November Cyclonic depressions in Andaman sea cause heavy rainfall and are destructive 
hope it helps

Answer 2

Here's your answer Buddy,

By mid-September the South-West monsoon begins to withdraw from the Indian Sub-continent. The retreating process gets accelerated gradually as the pressure over the lands gets higher than the sea. Cool winds begins to blow from the North side and the South-West monsoon starts moving backward.

Hope it helps.......^•^