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SAI INTERNATIONAL SCHOOL, BHUBANESWAR.
Class- IX: SOCIAL STUDIES – GEOGRAPHY
CHAPTER - 4- CLIMATE
(VIRTUAL CLASSES)
MODULE No.:07
NOTES FOR CHAPTER-4- CLIMATE
1. Sub Topic- Seasons- Advancing Monsoon (Rainy Season) and
Retreating/Post Monsoons (The Transition Season) (pg 33-35)
Advancing Monsoon
By the first week of June, low pressure conditions get intensified over the North
Indian Plains. Theseconditions attract the southeast trade winds which originate
from the Southern oceans.
These winds blow over the warm oceans and thus bring moisture and rainfall to
the country.
During the early monsoon season, the places located on the windward side of the
Western Ghatsreceive heavy rainfall up to 250 cm.
The northeastern parts of the country receive heavy rainfall. Mawsynram in
Meghalaya receives thehighest amount of rainfall in the world.
As we go from the east to the west, the rainfall decreases. Rajasthan and
Gujarat receive scantyrainfall.
Rain does not fall continuously during the monsoon season. Thus, there are dry
spells and wet spells.
Monsoons are uncertain and irregular.
Retreating Monsoon
During October and November, the southwest monsoon winds become weaker
and start retreatingfrom the Northern Plains by the beginning of October.
The retreat is indicated by clear skies and an increase in the temperature in the
northern plains. Thisincrease 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 easterncoast and the southern coast.
Most of the rainfall in the Coromandel Coast is derived from depressions and
cyclones.