NCERT Class 9 Geography Chapter 4 Notes

On this page, you will find NCERT Class 9 Geography Chapter 4 Notes Pdf free download. CBSE Class 9 Social Science Notes Geography Chapter 4 SST Climate will seemingly, help them to revise the important concepts in less time.

Climate Class 9 Notes Social Science Geography Chapter 4

CBSE Class 9 Geography Chapter 4 Notes Understanding the Lesson

1. Climate refers to the sum total of weather conditions and variations over a large area for a long period of time.

2. Weather refers to the state of the atmosphere over an area at any point of time.

3. The elements of weather and climate are the same i.e., temperature, atmospheric pressure, wind, humidity and precipitation.

4. The climate of India is described as the monsoon type. Temperature and precipitation vary from place to place and season to season.

5. In upper parts of Himalayas precipitation is mostly in the form of snowfall but in the rest of the country it rains. Most parts of the country receives rainfall from June to September. There is decrease in rainfall generally from east to west in the Northern Plains.

6. There are six major controls of the climate of any place-latitude, altitude, pressure and wind system, distance from the sea, ocean currents and relief features.

7. India’s climate has characteristics of tropical as well as sub-tropical climates. The Himalayas in the north of India prevent the cold winds from Central Asia from entering the sub-continent.

8. The climate and associated weather conditions in India are governed by-pressure and surface winds, upper air circulation; and western cyclonic disturbances and tropical cyclones.

9. The pressure and wind conditions over India are unique. During winter, there is a high-pressure area north of the Himalayas. In summer, a low-pressure area develops over interior Asia as well as over northwestern India.

10. The climate of India is strongly influenced by monsoon winds. The monsoons are experienced in the tropical area roughly between 20°N and 20°S.

11. The duration of monsoon in India is between 100-120 days from early June to mid-September. It arrives at the southern tip of the Indian peninsula by the first week of June. Subsequently, it proceeds into two-the Arabian sea branch and the Bay of Bengal branch.

12. The Arabian sea branch reaches Mumbai by the 10th of June and the Bay of Bengal branch arrives in Assam in the first week of June. Both these branches merge over the northwestern part of the Ganga plains.

13. The retreat of the monsoon begins in northwestern states of India by early September. By mid- October, it withdraws completely from the northern half of the peninsula. By early December, the monsoon has withdrawn from the rest of the country.

14. Four seasons can be identified in India-the cold-weather season, the hot weather season, the advancing monsoon and the retreating monsoon with some regional variations.

15. The cold-weather season begins from mid-November in northern India and stays till February. The hot-weather season remains from March to May. The rainy season starts from early June. By the beginning of October, the monsoon withdraws from the Northern plains.

16. December and January are the coldest in the northern part of India. The summer months experience rising temperature and falling air pressure in this part.

17. ‘Loo’ is a striking feature of the hot weather season. It blows over the north and northwestern India.

18. The retreat of monsoon is marked by clear skies and rise in temperature. While day temperature are high, nights are cool and pleasant.

19. Distribution of rainfall varies from place to place. It is highest in parts of western coast and northeastern India and lowest in western Rajasthan and adjoining parts of Gujarat, Haryana and Punjab.

20. Areas of high rainfall are liable to be affected by floods and areas of low rainfall are drought-prone.

21. The uncertainties of rain and uneven distribution are very much typical of the monsoons. The Indian landscape, its animal and plant life, its entire agriculture calender and the life of the people, revolve around this phenomenon.

Climate Class 9 CBSE Notes Important Terms

Weather: The state of atmosphere over an area of at any point of time.

Climate: The sum total of weather conditions and variation over a large area for a long period of time.

Monsoon: The seasonal prevailing wind in the region of South and South East Asia, blowing from the south-west between May and September and bringing rain.

Precipitation: Rain, snow, sleet or hail that falls to or condenses on the ground.

Loo: Strong, gusty, hot, dry winds blowing during the day over the north and north-western India.

Mahawat: The local name for the total amount of winter rainfall.

Relief: The highest and lowest elevation points in an area.