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What are the elements of weather, and how do we measure them?

Identify the main elements of weather and describe how each is measured using standard instruments

A clear, scaffolded answer to the N(A)-Level Geography outcome on weather measurement. The elements of weather (temperature, rainfall, humidity, wind, pressure, sunshine) and the instruments used to measure each.

Generated by Claude Opus 4.88 min answer

Reviewed by: AI editorial process; not yet individually human-reviewed

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  1. What this dot point is asking
  2. The answer
  3. Examples in context
  4. Try this

What this dot point is asking

This outcome asks you to name the elements that make up the weather and to describe how each is measured with the correct instrument and unit. Weather measurement links to the skills strand and to data-response questions. The central idea is that weather is made up of several measurable elements, and each has a standard instrument and a correct way of being used so that readings are fair and comparable.

The answer

The elements of weather

Weather is the day-to-day state of the atmosphere. Its main elements are:

  • Temperature: how hot or cold the air is.
  • Rainfall (precipitation): how much water falls from the sky.
  • Humidity: how much water vapour is in the air.
  • Wind: the speed and direction of moving air.
  • Air pressure: the weight of the air pressing down.
  • Sunshine and cloud: how much sun reaches the ground and how cloudy it is.

Measuring temperature

Temperature is measured with a thermometer, in degrees Celsius. To get a true reading of the air temperature, the thermometer is kept in a Stevenson screen: a white, louvred box that gives shade from direct sun, reflects heat with its white colour, lets air flow through its slats, and is raised off the ground. A maximum-minimum thermometer records the highest and lowest temperatures of the day.

Measuring rainfall

Rainfall is measured with a rain gauge, in millimetres. A funnel collects rain into a measuring cylinder. The gauge is placed in the open, away from buildings and trees, with the funnel a set height above the ground to avoid splash. It is read at the same time each day and then emptied.

Measuring humidity

Humidity is measured with a hygrometer (often a wet-and-dry-bulb thermometer). The difference between the two thermometer readings is used to work out the relative humidity, given as a percentage. High humidity means the air holds a lot of water vapour, which is typical of tropical climates.

Measuring wind, pressure and sunshine

  • Wind speed is measured with an anemometer (in kilometres or metres per second), and wind direction with a wind vane, which points to where the wind is coming from.
  • Air pressure is measured with a barometer, in millibars. Falling pressure often signals wet, stormy weather.
  • Sunshine is measured with a sunshine recorder, in hours.

Examples in context

Example 1. A school weather station in Singapore. A school weather station uses a Stevenson screen for the thermometers, a rain gauge in an open field, and an anemometer and wind vane on a mast. Reading them at the same time each day lets students track Singapore's hot, humid, rainy equatorial weather and build climate graphs from their own data.

Example 2. The national weather service. Singapore's Meteorological Service measures the same elements with professional instruments across many stations, feeding the data into forecasts and climate records. Accurate, consistent measurement is what makes a reliable rainfall warning or temperature forecast possible.

Try this

Q1. Name the instrument used to measure wind speed and the instrument used to measure wind direction. [2 marks]

  • Cue. An anemometer measures wind speed; a wind vane shows wind direction.

Q2. State the unit used to record rainfall and the unit used to record air pressure. [2 marks]

  • Cue. Rainfall in millimetres (mm); air pressure in millibars.

Q3. Explain one feature of a Stevenson screen and how it helps give an accurate temperature. [2 marks]

  • Cue. The white colour (or louvred sides) reflects sunlight and lets air flow, keeping the thermometer shaded so it reads the true air temperature, not the heat of the sun.

Exam-style practice questions

Practice questions written in the style of SEAB exam questions on this dot point, with worked answer explainers. The year tag is the paper they imitate, not the source.

Original6 marks(a) Name the instrument used to measure rainfall and state the unit it is recorded in. (b) Describe how a rain gauge is used correctly to give an accurate reading.
Show worked answer →

(a) Rainfall is measured with a rain gauge, and it is recorded in millimetres (mm).

(b) A rain gauge is a container with a funnel that collects rain into a measuring cylinder. To give an accurate reading it should be placed in the open, away from buildings and trees that would block or drip extra rain, with the top of the funnel a set height above the ground to avoid splash. The water collected is read off at the same time each day (for example daily) and the gauge is then emptied.

What markers reward: naming the rain gauge and the unit (mm), and correct use such as siting it in the open away from obstacles, reading it at a fixed time, and emptying it after.

Original5 marksExplain why a thermometer used to measure air temperature is kept inside a Stevenson screen.
Show worked answer →

A Stevenson screen is a white, louvred (slatted) box that holds weather instruments such as thermometers. It keeps the thermometer in the shade so it measures the true air temperature, not the heat of direct sunlight.

The white colour reflects sunlight, the louvres let air flow freely around the thermometer, and it is raised off the ground to avoid heat from the surface. Together these give a fair, accurate and comparable reading of the air temperature.

What markers reward: shade from direct sun for a true air-temperature reading, the white colour reflecting heat, the louvres allowing free air flow, and being raised off the ground.

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