Worksheets › Class 7 › Understanding the Weather › Cheat sheet
Class 7 Understanding the Weather: cheat sheet
CBSE Social Science. The elements of weather, the instruments and units used to measure them, temperature range and mean, air pressure and how forecasts help us.
Key ideas
- Weather is the state of the atmosphere at a given time and place; climate is the pattern of weather over decades.
- The five elements of weather are temperature, air pressure, wind, precipitation and humidity.
- Almost all weather happens in the troposphere, the lowest layer of the atmosphere.
- Wind blows from high pressure to low pressure; air pressure is lower on high places because less air presses down.
- Humidity is the water vapour in the air; at 100 per cent relative humidity the air is saturated.
- Rain, snow, sleet and hail are all forms of precipitation.
- Forecasts help farmers decide when to sow, water or harvest, and warn people before storms.
Remember
| Temperature range | highest − lowest |
| Mean temperature | (highest + lowest) ÷ 2 |
| Rain gauge | measures rainfall, in millimetres |
| Wind vane / anemometer | wind direction / wind speed |
| Air pressure | in millibars; about 1013 at the coast; below about 1000 can mean a storm |
| IMD | India Meteorological Department, set up in 1875 |
| Loo | hot, dusty summer winds of north India |
Watch out
- Mixing up weather (today) and climate (the long-term pattern).
- Mixing up a wind vane (direction) and an anemometer (speed).
- Saying wind blows from low to high pressure: it blows from high to low.
Worked example
One day the highest temperature was 40 °C and the lowest 32 °C. Find (a) the range and (b) the mean temperature.
Working: 40 − 32; (40 + 32) ÷ 2
Answer: (a) 8 °C (b) 36 °C
Practise Understanding the Weather
Revise with this page, then practise: every Understanding the Weather sheet in the app is new, with an answer key and working.
Coming soon for Android and iPhone.