Chapter 2: Understanding the WeatherClass 7 Social Science — summary, notes, extra questions & NCERT solutions

Summary

This chapter explains what weather is and how we measure and predict it. Weather is the state of the Earth's atmosphere at a particular time and place, and it happens mostly in the troposphere, the layer of air closest to the ground. Five elements define the weather: temperature, precipitation, atmospheric pressure, wind and humidity. The chapter shows why common standards of measurement matter — what feels chilly to someone in Chennai may feel pleasant to someone in Kashmir — and introduces the instruments scientists use: the thermometer for temperature (on the Celsius and Fahrenheit scales), the rain gauge for rainfall in millimetres, the barometer for atmospheric pressure in millibars, the wind vane and anemometer for wind direction and speed, and the hygrometer for relative humidity. It traces how people once read nature's clues — ants moving eggs, frogs croaking, pine cones opening — to forecast weather, and how meteorologists now use instruments and weather stations, including Automated Weather Stations, to collect data over time. The India Meteorological Department, set up in 1875, issues colour-coded warnings for events like heat waves, heavy rain and cyclones. The chapter stresses that accurate weather prediction helps people plan activities, lets governments prepare for disasters, and saves lives, especially as climate change makes extreme weather more frequent.

Key terms

Extra questions & answers

LET'S EXPLORE

THINK ABOUT IT

LET'S EXPLORE

LET'S EXPLORE

LET'S EXPLORE

DON'T MISS OUT

LET'S EXPLORE

THINK ABOUT IT

THINK ABOUT IT

LET'S EXPLORE

THINK ABOUT IT

LET'S EXPLORE

LET'S EXPLORE

Questions and activities

Explore interactively