Class 4 - EVS - Weather and Climate

Learning Objectives

Understand the difference between weather (daily) and climate (long-term pattern).
Know the factors that affect weather: temperature, humidity, wind, and rainfall.
Learn about weather instruments: thermometer, rain gauge, and wind vane.
Know the seasons in India and the months they cover.
Understand how climate affects houses, food, and clothing in different regions of India.

A Friendly Introduction

Have you noticed that some days are hot and sunny, while other days are rainy or cold? The condition of the air around us at a particular time and place is called weather. Weather can change from hour to hour and day to day. But if we observe the weather of a place over many years, we get a pattern -- that pattern is called climate. For example, Chennai is usually hot and humid, while Shimla is usually cool. That is their climate.

Weather vs Climate

Weather	Climate
Day-to-day condition of the atmosphere	Average weather pattern of a place over 25-30 years
Changes quickly -- can change in hours	Does not change quickly -- stays the same for years
Example: "Today is a rainy day in Delhi."	Example: "Rajasthan has a hot and dry climate."

Think: If someone asks, "How is the weather today?" they want to know about today. If they ask, "What is the climate of Kerala?" they want to know the usual pattern over many years.

Factors Affecting Weather

Four main factors decide what the weather will be like:

Factor	What It Means	Example
Temperature	How hot or cold the air is	Summer days in Nagpur can reach 45 degrees Celsius
Humidity	The amount of moisture (water vapour) in the air	Mumbai feels sticky in June because humidity is high
Wind	Moving air -- can be gentle or strong	Strong winds blow during cyclones along the coast of Odisha
Rainfall	Water falling from clouds as rain	Cherrapunji in Meghalaya receives very heavy rainfall

Weather Instruments

Scientists use special instruments to measure weather:

Instrument	What It Measures	Unit
Thermometer	Temperature (how hot or cold)	Degrees Celsius
Rain Gauge	Amount of rainfall	Millimetres (mm)
Wind Vane	Direction of the wind	North, South, East, West

Example: Reading a Thermometer

If the thermometer at your school in Jaipur shows 40 degrees Celsius in May, it means the day is very hot. If it shows 10 degrees Celsius in Srinagar in January, it means the day is very cold.

Seasons in India

Season	Months	What It Is Like
Summer (Grishma)	March to May	Very hot, dry winds (called loo in North India)
Monsoon / Rainy (Varsha)	June to September	Heavy rainfall, cloudy skies, cooler than summer
Autumn (Sharad)	October to November	Pleasant weather, clear skies, festivals like Diwali and Dussehra
Winter (Shishir / Hemant)	December to February	Cold weather, fog in North India, short days

Key Words

Word	Meaning
Weather	The day-to-day condition of the atmosphere at a place
Climate	The average weather pattern of a place over many years
Temperature	A measure of how hot or cold something is
Humidity	The amount of water vapour (moisture) in the air
Thermometer	An instrument used to measure temperature

How Climate Affects Life in Different Regions

People in different parts of India live differently because of their climate.

Region	Climate	Houses	Food	Clothing
Rajasthan	Hot and dry	Thick walls, small windows to keep heat out	Dry foods like dal-baati, less green vegetables	Light cotton clothes, turbans to protect from sun
Kerala	Hot and wet	Sloping roofs so rain water slides off	Rice, coconut, fish	Light cotton clothes
Kashmir	Very cold	Wooden houses with sloping roofs for snow	Meat, dry fruits, kahwa (warm tea)	Thick woollen clothes, shawls, pheran
Assam	Warm and wet	Houses on stilts (raised) to avoid floods	Rice, fish, bamboo shoot dishes	Cotton and silk (mekhela chador)

Example: Why Do Houses Differ?

In Cherrapunji (Meghalaya), one of the wettest places on Earth, houses have steep sloping roofs so that heavy rain flows off quickly. In Jaisalmer (Rajasthan), houses have thick stone walls and small windows to keep the hot desert air out and the inside cool.

Key Points to Remember

Weather is the daily condition of the atmosphere. Climate is the long-term pattern over many years.
Temperature, humidity, wind, and rainfall are the main factors affecting weather.
A thermometer measures temperature. A rain gauge measures rainfall. A wind vane shows wind direction.
India has four main seasons: Summer, Monsoon, Autumn, and Winter.
Climate affects the type of houses, food, and clothing in different regions of India.

Practice Questions

A. Fill in the Blanks

The day-to-day condition of the atmosphere is called .
The average weather pattern over many years is called .
A is used to measure temperature.
The monsoon season in India lasts from to .
Houses in Kerala have roofs because of heavy rainfall.

B. True or False

Weather and climate mean the same thing.
A rain gauge measures the direction of wind.
Rajasthan has a hot and dry climate.
People in Kashmir wear light cotton clothes in winter.

C. Multiple Choice Questions

Which instrument measures the direction of wind?
(a) Thermometer(b) Rain gauge(c) Wind vane(d) Clock
Which season in India brings heavy rainfall?
(a) Summer(b) Winter(c) Autumn(d) Monsoon
Houses in Assam are built on stilts to protect from:
(a) Heat(b) Floods(c) Snow(d) Wind

D. Short Answer Questions

Write two differences between weather and climate.
Why do houses in Rajasthan have thick walls and small windows?

Fun Activity -- My Weather Diary

Observe the weather for 5 days and fill in the table below.

Day	Sunny / Cloudy / Rainy	Hot / Warm / Cold	Windy? (Yes / No)
Day 1
Day 2
Day 3
Day 4
Day 5

Did the weather stay the same or change over 5 days?

Science / EVS -- Class 4

Science / EVS -- Class 4 (continued)