Class 7 Social Science Chapter 2 NCERT Book - Understanding the Weather

 Page 1


27
India and the World: Land and the People 
2 – Understanding the Weather
Understanding  
the Weather
CHAPTER
2
A change in the weather is sufficient to create 
the world and oneself anew.
    Marcel Proust, French novelist
1. How can we measure and 
monitor the weather around us?
2. How do weather predictions 
help us prepare for events like 
heavy rain, storms, drought and 
heat waves?
The Big 
Questions
Fig. 2.1
Chapter 2.indd   27 Chapter 2.indd   27 08-04-2025   12:42:20 08-04-2025   12:42:20
Page 2


27
India and the World: Land and the People 
2 – Understanding the Weather
Understanding  
the Weather
CHAPTER
2
A change in the weather is sufficient to create 
the world and oneself anew.
    Marcel Proust, French novelist
1. How can we measure and 
monitor the weather around us?
2. How do weather predictions 
help us prepare for events like 
heavy rain, storms, drought and 
heat waves?
The Big 
Questions
Fig. 2.1
Chapter 2.indd   27 Chapter 2.indd   27 08-04-2025   12:42:20 08-04-2025   12:42:20
28
Exploring Society: India and Beyond | Grade 7 Part 1
Weather and its Elements
You wake up one winter morning and shiver. You reach for 
thick clothes to keep yourself warm. In the summer, you choose 
clothes that keep you cool and comfortable. You are responding 
to your body’s signals; your body is sensing the weather. 
What is weather?
Weather is a state of 
the Earth’s atmosphere 
at a particular time and 
place. But what is an 
atmosphere? In simple 
terms, it is the layer of 
gases that surround 
some planets?—?in the 
case of our Earth, we 
call these gases ‘air’. The 
Earth’s atmosphere may 
be compared to a cake 
with several layers. The layer closest to the surface of the Earth is 
called the ‘troposphere’, and that is where all land-based plants 
and animals (including humans!) live and breathe. It is also 
where almost all weather phenomena, which we will explore in 
this chapter, take place. The troposphere extends to a height of 
6 to 18 kilometres from the ground; it is less thick at the poles 
(where the cold air contracts) and thicker in the tropical zone 
(where the warmer air expands). You will study more about the 
other layers in your Science classes.  
We use many words to describe the weather?—?hot, cold, rainy, 
cloudy, humid, snowy, windy, and so on. They describe the 
different ways in which we experience the elements of weather. 
LET’S EXPLORE
What are some of the words in your local language that you 
use to describe the weather? Hot, cold, warm, chilly, crisp, 
pleasant, and so on, are commonly used terms in English.
Stratosphere
Tropopause Ozone Layer
Troposphere
Fig. 2.2
Chapter 2.indd   28 Chapter 2.indd   28 08-04-2025   12:42:20 08-04-2025   12:42:20
Page 3


27
India and the World: Land and the People 
2 – Understanding the Weather
Understanding  
the Weather
CHAPTER
2
A change in the weather is sufficient to create 
the world and oneself anew.
    Marcel Proust, French novelist
1. How can we measure and 
monitor the weather around us?
2. How do weather predictions 
help us prepare for events like 
heavy rain, storms, drought and 
heat waves?
The Big 
Questions
Fig. 2.1
Chapter 2.indd   27 Chapter 2.indd   27 08-04-2025   12:42:20 08-04-2025   12:42:20
28
Exploring Society: India and Beyond | Grade 7 Part 1
Weather and its Elements
You wake up one winter morning and shiver. You reach for 
thick clothes to keep yourself warm. In the summer, you choose 
clothes that keep you cool and comfortable. You are responding 
to your body’s signals; your body is sensing the weather. 
What is weather?
Weather is a state of 
the Earth’s atmosphere 
at a particular time and 
place. But what is an 
atmosphere? In simple 
terms, it is the layer of 
gases that surround 
some planets?—?in the 
case of our Earth, we 
call these gases ‘air’. The 
Earth’s atmosphere may 
be compared to a cake 
with several layers. The layer closest to the surface of the Earth is 
called the ‘troposphere’, and that is where all land-based plants 
and animals (including humans!) live and breathe. It is also 
where almost all weather phenomena, which we will explore in 
this chapter, take place. The troposphere extends to a height of 
6 to 18 kilometres from the ground; it is less thick at the poles 
(where the cold air contracts) and thicker in the tropical zone 
(where the warmer air expands). You will study more about the 
other layers in your Science classes.  
We use many words to describe the weather?—?hot, cold, rainy, 
cloudy, humid, snowy, windy, and so on. They describe the 
different ways in which we experience the elements of weather. 
LET’S EXPLORE
What are some of the words in your local language that you 
use to describe the weather? Hot, cold, warm, chilly, crisp, 
pleasant, and so on, are commonly used terms in English.
Stratosphere
Tropopause Ozone Layer
Troposphere
Fig. 2.2
Chapter 2.indd   28 Chapter 2.indd   28 08-04-2025   12:42:20 08-04-2025   12:42:20
29
India and the World: Land and the People 
2 – Understanding the Weather
The elements of weather are:
 ? Temperature: How hot or cold the atmosphere is.
 ? Precipitation: Any form of water, such as rain, snow, sleet 
or hail, that falls from the sky.
 ? Atmospheric Pressure: The weight of the air above us, felt 
on the Earth’s surface.
 ? Wind: The movement of air, including its speed  
and direction.
 ? Humidity: The amount of water vapour in the air.
THINK ABOUT IT
Let us imagine that Krishnan from Chennai is speaking with 
Amir in Kashmir. Krishnan tells Amir that it has become 
chilly in Chennai after it rained the previous night. Amir asks 
him how cold it is. How will Krishnan explain to Amir how 
cold it is? After all, what is cold for Krishnan may be quite 
pleasant for Amir!
As you can see, it would be difficult for Krishnan to convey his 
sense of chillness to Amir unless there is a commonly agreed way 
to measure the temperature. It is the same with other elements 
of the weather. In this chapter, we will learn how we measure 
the weather using common standards.  
LET’S EXPLORE
What do you think could be some other reasons to measure 
the weather more precisely? (Hint: Think how knowing the 
weather a few hours or a few days in advance would help you 
plan some activities.)
From early times, humans have closely observed Nature and 
learnt to read her signals to forecast the weather . Observing birds 
flying low, ants carrying eggs, squirrels gathering nuts, frogs 
croaking loudly, or even the opening and closing of pine cones, 
provided valuable information about coming rain or storms. This 
knowledge has been passed down from generation to generation. 
Even today, in many parts of India, people use traditional ways 
to predict the weather, especially the arrival of the monsoon.
Water vapour:
Water vapour 
is water in 
gaseous 
instead of 
liquid form. 
Sleet:
Frozen or partly 
frozen rain.
Hail:
Small, hard 
balls of ice that 
fall from the 
sky like rain.
Forecast: 
To predict 
or find 
out in 
advance 
(in our 
case, the 
weather).
Chapter 2.indd   29 Chapter 2.indd   29 08-04-2025   12:42:20 08-04-2025   12:42:20
Page 4


27
India and the World: Land and the People 
2 – Understanding the Weather
Understanding  
the Weather
CHAPTER
2
A change in the weather is sufficient to create 
the world and oneself anew.
    Marcel Proust, French novelist
1. How can we measure and 
monitor the weather around us?
2. How do weather predictions 
help us prepare for events like 
heavy rain, storms, drought and 
heat waves?
The Big 
Questions
Fig. 2.1
Chapter 2.indd   27 Chapter 2.indd   27 08-04-2025   12:42:20 08-04-2025   12:42:20
28
Exploring Society: India and Beyond | Grade 7 Part 1
Weather and its Elements
You wake up one winter morning and shiver. You reach for 
thick clothes to keep yourself warm. In the summer, you choose 
clothes that keep you cool and comfortable. You are responding 
to your body’s signals; your body is sensing the weather. 
What is weather?
Weather is a state of 
the Earth’s atmosphere 
at a particular time and 
place. But what is an 
atmosphere? In simple 
terms, it is the layer of 
gases that surround 
some planets?—?in the 
case of our Earth, we 
call these gases ‘air’. The 
Earth’s atmosphere may 
be compared to a cake 
with several layers. The layer closest to the surface of the Earth is 
called the ‘troposphere’, and that is where all land-based plants 
and animals (including humans!) live and breathe. It is also 
where almost all weather phenomena, which we will explore in 
this chapter, take place. The troposphere extends to a height of 
6 to 18 kilometres from the ground; it is less thick at the poles 
(where the cold air contracts) and thicker in the tropical zone 
(where the warmer air expands). You will study more about the 
other layers in your Science classes.  
We use many words to describe the weather?—?hot, cold, rainy, 
cloudy, humid, snowy, windy, and so on. They describe the 
different ways in which we experience the elements of weather. 
LET’S EXPLORE
What are some of the words in your local language that you 
use to describe the weather? Hot, cold, warm, chilly, crisp, 
pleasant, and so on, are commonly used terms in English.
Stratosphere
Tropopause Ozone Layer
Troposphere
Fig. 2.2
Chapter 2.indd   28 Chapter 2.indd   28 08-04-2025   12:42:20 08-04-2025   12:42:20
29
India and the World: Land and the People 
2 – Understanding the Weather
The elements of weather are:
 ? Temperature: How hot or cold the atmosphere is.
 ? Precipitation: Any form of water, such as rain, snow, sleet 
or hail, that falls from the sky.
 ? Atmospheric Pressure: The weight of the air above us, felt 
on the Earth’s surface.
 ? Wind: The movement of air, including its speed  
and direction.
 ? Humidity: The amount of water vapour in the air.
THINK ABOUT IT
Let us imagine that Krishnan from Chennai is speaking with 
Amir in Kashmir. Krishnan tells Amir that it has become 
chilly in Chennai after it rained the previous night. Amir asks 
him how cold it is. How will Krishnan explain to Amir how 
cold it is? After all, what is cold for Krishnan may be quite 
pleasant for Amir!
As you can see, it would be difficult for Krishnan to convey his 
sense of chillness to Amir unless there is a commonly agreed way 
to measure the temperature. It is the same with other elements 
of the weather. In this chapter, we will learn how we measure 
the weather using common standards.  
LET’S EXPLORE
What do you think could be some other reasons to measure 
the weather more precisely? (Hint: Think how knowing the 
weather a few hours or a few days in advance would help you 
plan some activities.)
From early times, humans have closely observed Nature and 
learnt to read her signals to forecast the weather . Observing birds 
flying low, ants carrying eggs, squirrels gathering nuts, frogs 
croaking loudly, or even the opening and closing of pine cones, 
provided valuable information about coming rain or storms. This 
knowledge has been passed down from generation to generation. 
Even today, in many parts of India, people use traditional ways 
to predict the weather, especially the arrival of the monsoon.
Water vapour:
Water vapour 
is water in 
gaseous 
instead of 
liquid form. 
Sleet:
Frozen or partly 
frozen rain.
Hail:
Small, hard 
balls of ice that 
fall from the 
sky like rain.
Forecast: 
To predict 
or find 
out in 
advance 
(in our 
case, the 
weather).
Chapter 2.indd   29 Chapter 2.indd   29 08-04-2025   12:42:20 08-04-2025   12:42:20
30
Exploring Society: India and Beyond | Grade 7 Part 1
LET’S EXPLORE
Talk to elders in your neighbourhood and ask them how they 
predict the weather. What signs do they observe? Document 
any sayings in your regional language that refer to weather 
prediction. 
In the last few centuries, scientists have worked out methods to 
measure and monitor the elements of the weather with great 
precision. Based on those inputs, meteorologists try to predict 
how the weather will behave in a particular region after a few 
hours or a few days, or even a few weeks. How do they do it? Do 
they just look up at the sky and guess? No, they’ve got some cool 
gadgets, a few of which we will now look at. 
Meteorology:
Meteorology 
is the 
systematic 
study of 
weather and 
its evolution. 
This study 
is the basis 
for weather 
forecasting. 
Fig. 2.3.1. Ants shifting their eggs to 
higher ground is a natural behaviour 
that indicates an expected change in 
the weather , especially heavy rain.
Fig. 2.3.2. A frog 
croaking in a forest of 
the Western Ghats, in 
expectation of rain.
Fig. 2.3.3. The opening and closing of pine 
cones are natural mechanisms driven by 
environmental humidity. Pine cones close 
in humid conditions to protect their seeds, 
and open in dry conditions to release them, 
ensuring they spread in favourable weather .
Observing Nature’s clues
Chapter 2.indd   30 Chapter 2.indd   30 08-04-2025   12:42:23 08-04-2025   12:42:23
Page 5


27
India and the World: Land and the People 
2 – Understanding the Weather
Understanding  
the Weather
CHAPTER
2
A change in the weather is sufficient to create 
the world and oneself anew.
    Marcel Proust, French novelist
1. How can we measure and 
monitor the weather around us?
2. How do weather predictions 
help us prepare for events like 
heavy rain, storms, drought and 
heat waves?
The Big 
Questions
Fig. 2.1
Chapter 2.indd   27 Chapter 2.indd   27 08-04-2025   12:42:20 08-04-2025   12:42:20
28
Exploring Society: India and Beyond | Grade 7 Part 1
Weather and its Elements
You wake up one winter morning and shiver. You reach for 
thick clothes to keep yourself warm. In the summer, you choose 
clothes that keep you cool and comfortable. You are responding 
to your body’s signals; your body is sensing the weather. 
What is weather?
Weather is a state of 
the Earth’s atmosphere 
at a particular time and 
place. But what is an 
atmosphere? In simple 
terms, it is the layer of 
gases that surround 
some planets?—?in the 
case of our Earth, we 
call these gases ‘air’. The 
Earth’s atmosphere may 
be compared to a cake 
with several layers. The layer closest to the surface of the Earth is 
called the ‘troposphere’, and that is where all land-based plants 
and animals (including humans!) live and breathe. It is also 
where almost all weather phenomena, which we will explore in 
this chapter, take place. The troposphere extends to a height of 
6 to 18 kilometres from the ground; it is less thick at the poles 
(where the cold air contracts) and thicker in the tropical zone 
(where the warmer air expands). You will study more about the 
other layers in your Science classes.  
We use many words to describe the weather?—?hot, cold, rainy, 
cloudy, humid, snowy, windy, and so on. They describe the 
different ways in which we experience the elements of weather. 
LET’S EXPLORE
What are some of the words in your local language that you 
use to describe the weather? Hot, cold, warm, chilly, crisp, 
pleasant, and so on, are commonly used terms in English.
Stratosphere
Tropopause Ozone Layer
Troposphere
Fig. 2.2
Chapter 2.indd   28 Chapter 2.indd   28 08-04-2025   12:42:20 08-04-2025   12:42:20
29
India and the World: Land and the People 
2 – Understanding the Weather
The elements of weather are:
 ? Temperature: How hot or cold the atmosphere is.
 ? Precipitation: Any form of water, such as rain, snow, sleet 
or hail, that falls from the sky.
 ? Atmospheric Pressure: The weight of the air above us, felt 
on the Earth’s surface.
 ? Wind: The movement of air, including its speed  
and direction.
 ? Humidity: The amount of water vapour in the air.
THINK ABOUT IT
Let us imagine that Krishnan from Chennai is speaking with 
Amir in Kashmir. Krishnan tells Amir that it has become 
chilly in Chennai after it rained the previous night. Amir asks 
him how cold it is. How will Krishnan explain to Amir how 
cold it is? After all, what is cold for Krishnan may be quite 
pleasant for Amir!
As you can see, it would be difficult for Krishnan to convey his 
sense of chillness to Amir unless there is a commonly agreed way 
to measure the temperature. It is the same with other elements 
of the weather. In this chapter, we will learn how we measure 
the weather using common standards.  
LET’S EXPLORE
What do you think could be some other reasons to measure 
the weather more precisely? (Hint: Think how knowing the 
weather a few hours or a few days in advance would help you 
plan some activities.)
From early times, humans have closely observed Nature and 
learnt to read her signals to forecast the weather . Observing birds 
flying low, ants carrying eggs, squirrels gathering nuts, frogs 
croaking loudly, or even the opening and closing of pine cones, 
provided valuable information about coming rain or storms. This 
knowledge has been passed down from generation to generation. 
Even today, in many parts of India, people use traditional ways 
to predict the weather, especially the arrival of the monsoon.
Water vapour:
Water vapour 
is water in 
gaseous 
instead of 
liquid form. 
Sleet:
Frozen or partly 
frozen rain.
Hail:
Small, hard 
balls of ice that 
fall from the 
sky like rain.
Forecast: 
To predict 
or find 
out in 
advance 
(in our 
case, the 
weather).
Chapter 2.indd   29 Chapter 2.indd   29 08-04-2025   12:42:20 08-04-2025   12:42:20
30
Exploring Society: India and Beyond | Grade 7 Part 1
LET’S EXPLORE
Talk to elders in your neighbourhood and ask them how they 
predict the weather. What signs do they observe? Document 
any sayings in your regional language that refer to weather 
prediction. 
In the last few centuries, scientists have worked out methods to 
measure and monitor the elements of the weather with great 
precision. Based on those inputs, meteorologists try to predict 
how the weather will behave in a particular region after a few 
hours or a few days, or even a few weeks. How do they do it? Do 
they just look up at the sky and guess? No, they’ve got some cool 
gadgets, a few of which we will now look at. 
Meteorology:
Meteorology 
is the 
systematic 
study of 
weather and 
its evolution. 
This study 
is the basis 
for weather 
forecasting. 
Fig. 2.3.1. Ants shifting their eggs to 
higher ground is a natural behaviour 
that indicates an expected change in 
the weather , especially heavy rain.
Fig. 2.3.2. A frog 
croaking in a forest of 
the Western Ghats, in 
expectation of rain.
Fig. 2.3.3. The opening and closing of pine 
cones are natural mechanisms driven by 
environmental humidity. Pine cones close 
in humid conditions to protect their seeds, 
and open in dry conditions to release them, 
ensuring they spread in favourable weather .
Observing Nature’s clues
Chapter 2.indd   30 Chapter 2.indd   30 08-04-2025   12:42:23 08-04-2025   12:42:23
31
India and the World: Land and the People 
2 – Understanding the Weather
Weather Instruments
a) Temperature
LET’S REMEMBER
In your Grade 6 Science textbook, Curiosity, you read about 
different types of thermometers used for measuring the 
temperature — the clinical thermometer and the laboratory 
thermometer. You also learnt about temperature scales. 
One of them is the Celsius scale; another is the Fahrenheit 
scale. If, for instance, we have a cool temperature of 15 
degrees Celsius (noted as 15°C), it is the same as 59 degrees 
Fahrenheit (noted as 59°F).
Fig. 2.4.3. In winter , 
coconut oil turns solid.
Fig. 2.4.2. Cloudy weather ?it’s 
getting cold.
Fig. 2.4.1. Snow melts 
quickly when it’s warm.
Fig. 2.4.4. Curd takes longer 
to set in cold weather .
Chapter 2.indd   31 Chapter 2.indd   31 08-04-2025   12:42:26 08-04-2025   12:42:26