Understanding the Weather Class 7 Notes

Understanding the Weather: Weather is a part of our daily life. It changes every day and affects our way of eating, wearing clothes, and more. Sometimes it is sunny and warm, while at other times, it rains or becomes cold. Understanding the weather helps us plan our day and stay safe during storms or heatwaves.

What is Weather?

Weather refers to the condition of the air in a place for a short time. It includes things like sunshine, rain, wind, clouds, and temperature. When we say it is a ‘hot day’ or ‘rainy evening’, we are talking about the weather.

• The weather changes quickly. It may be clear in the morning and cloudy by afternoon. These changes happen because of the movement of air, water vapour, and heat from the Sun.
  
• The Sun’s energy warms the land and water, and this heat makes the air move, forming wind and clouds.
  
• The study of weather is called meteorology, and the person who studies it is a meteorologist. They use different tools to measure and record weather changes.

Difference Between Weather and Climate

The weather changes every day, but climate refers to the usual weather of a place over many years. For example, Rajasthan has a hot and dry climate, while Kerala has a wet and warm one.

Elements of Weather

The weather depends on several parts, also known as elements. Each element helps us understand the condition of the air.

• Temperature: It tells how hot or cold the air is. It is measured with a thermometer.
  
• Wind: Air moves from one place to another, and this movement is called wind. Gentle wind keeps us cool, while strong wind can cause storms.
  
• Humidity: It shows how much water vapour is present in the air. When humidity is high, the air feels sticky.
  
• Rainfall: When water drops fall from clouds, we call it rain. It helps plants grow and fills rivers and ponds.
  
• Air Pressure: Air presses on the surface of the Earth. Changes in air pressure help to predict rain and storms.

Weather Instruments

Some of the special tools used by scientists to study and record the weather are as follows:

• Thermometer: Measures temperature.
• Rain Gauge: Collects and measures the amount of rainfall.
• Barometer: Checks air pressure.
• Wind Vane: Shows the direction of the wind.
• Anemometer: Measures wind speed.