CBSE Class 9 Geography Chapter 4 Notes - Climate

Download PDF

Climate Class 9 Notes Geography Chapter 4 - PDF Download

In Class 9 Geography Chapter 4 Climate revision notes, we come to learn that the word ‘Climate’ is derived from the word “Klima” which means ‘inclination’ in Greek. Over the years, ‘Klima’ evolved into ‘clime’ which later went on to mean the atmospheric condition of a region. Climate indicates the average weather condition of a particular place for 30 years or more. The factors that characterise the climate of a place are temperature, air pressure, wind, humidity, precipitation, etc. of a place throughout the year. Download the notes on Vedantu to know more about the chapter.

Do you need help with your Homework? Are you preparing for Exams?
Study without Internet (Offline)
CBSE Class 9 Geography Chapter 4 Notes - Climate part-1

Definition of Weather in Climate Chapter Class 9 Notes

The term weather denotes the atmospheric condition of a particular place for one day or a few hours. It depends upon temperature, humidity, wind speed, etc.

Difference Between Climate and Weather in Climate Chapter Class 9 Notes

In Climate Geography Class 9, you will learn about climate and weather, and how they are different from each other. Though the components and variables of both climate and weather are the same, still there is a difference between the two.

Weather conditions of a place deal with the day-to-day variations of its atmospheric condition. On the other hand, the climate of a place is the average of the weather conditions for 30 years or more. Weather is frequently changeable but the climate is a standard concept for a given period of time.

Factors that Control the Climate of a Place

As discussed in the Climate Chapter Class 9 Notes, the following factors affect the climate of a geographical region:

  • Latitude: The places which are located near the equator receive direct rays of the sun throughout the year. So, the temperature remains high almost throughout the year. On the other hand, the places which are located near the poles receive slanting sun rays and thus have low temperature throughout the year.

  • Altitude: The temperature decreases by 6 degrees every 1km from the sea level; this is known as the normal lapse rate.

  • Distance From the Sea: The places which are located near the sea have a moderate climate, but regions which are located far away from the sea have an extreme type of climate. This happens because two types of wind always prevail near the coast i.e., land breeze and sea breeze.

  • Relief Features: The presence of some significant relief features also plays a role in shaping the climate of a place.

  • Humidity: The humidity of a place is highly affected by its distance from the sea.

  • Ocean Currents: If cold ocean currents are circulating near the shores of a country, then the country will have a cooler climatic condition than the country where warm ocean currents are active near the shores.

Factors Affecting India’s Climate

The factors which control the diversified climatic conditions of India are as follows:

  • Latitude - Places located in the northern part of India have a cold climate while places in the southern states have warm climatic conditions.

  • Altitude - Places located on the slopes of the Himalayas or other hill ranges have colder climates than the places on the plains.

  • Presence of Winds - In the north-west part of India, local winds prevail during summer months which control the climatic conditions of that region to a huge extent.

  • Relief - The relief features of a place, that is, whether it is on the plainland or located on the hills or plateaus determine the climatic conditions of a place.

You will learn about these factors in detail in Class 9 Geography Chapter 4 Climate notes.

Indian Monsoon in Climate Notes

Monsoon wind is a seasonal wind which mainly prevails in the south and south-east Asia. The Arabic word “mausim” meaning season is the origin of the term “monsoon.” During the months of May-September, it blows from south-west direction to the northeast direction and brings heavy rainfall in the Indian subcontinent. Again, during the Reverse Monsoon period, this wind blows from northeast to south-west.

Formation of Monsoon in Climate Class 9 Notes

Monsoon winds are generated due to the difference in the heating and cooling rates of land and sea. During the summer season, a high-pressure cell forms in the east of Madagascar and a low-pressure cell in the Tibetan plateau. Due to the presence of these two pressure cells, monsoon winds develop and enter India in two branches- the Bay of Bengal branch and the Arabian sea branch causing heavy rainfall. At the end of May, the monsoon hits the coast of Kerala and brings heavy rainfall in this region. It is also known as the Burst of Monsoon. All this is beautifully explained in the Class 9 Geography Chapter 4 Climate notes.

Seasons of India

The notes on Climate Geography Class 9 clearly speaks about the four seasons that are prevalent in India - summer, rainy, post-monsoon or transition period and the winter. During summer, in north-west India, a local hot wind prevails which is known as loo. Then, monsoon wind brings rains in the rainy season. After that, in the transition period, a mild climate prevails all over India. During winter, snowfall occurs in the northernmost and some northeastern parts of India.

To learn more about climate, download Climate Class 9 notes PDF download.

Did You Know?

How extreme India’s climate is!

  • Mawsynram in Meghalaya receives, on an average, 10,000 millilitres of rainfall in a year.

  • Rajasthan’s Churu is the hottest place in India. The temperature here reaches 50-degree Celsius during summer!

FAQ (Frequently Asked Questions)

Q1. Write a Short Note on the Distribution of Rainfall in India.

Ans. In the Climate notes, the distribution of rainfall in India is discussed vividly. The western coast of India and northeastern parts receive the maximum amount of rainfall, while the places in states like Rajasthan and Gujarat receive very less rainfall.

Based on climate, rainfall and soil condition, the vegetation changes. In India, the distribution of rainfall is quite uneven and uncertain too; so it also affects the agriculture period of the country to some extent.

Q2. What is the Time Period for Retreating Monsoon?

Ans. From early November till December, the phase of retreating monsoon continues. During this time, the south-west monsoon winds return from the Indian subcontinent as the northeast monsoon winds. Then, it blows as a dry land breeze, but while crossing the Bay of Bengal, it collects moistures and causes heavy rainfall in Tamil Nadu, along with Kerala, Karnataka, etc. With the retreating of Monsoon, rainfall started to decrease but during this time period, several cyclones are formed in the Bay of Bengal which causes heavy rainfall in the coastal regions.

Share this with your friends