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Learn · Climate & Atmosphere

What the Air Around Us Tells Us

Reading three invisible measurements that describe your environment

Grades 6–8 30 min observation live IESH data

Students take their first readings from the sensor hub, learn what temperature, humidity and pressure actually measure, and connect those numbers to what they can feel and observe outside.

Learning objectives

  • Explain what temperature, humidity and atmospheric pressure measure in physical terms.
  • Read live sensor values and record them accurately in a data table.
  • Describe how the three measurements relate to what we feel as "weather".
  • Connect Nepal's geographical diversity to differences in climate across the country.

Background

Temperature measures how much kinetic energy the air molecules have — faster-moving molecules feel hot, slower ones feel cold. We measure it in degrees Celsius (°C). Air temperature changes through the day as the sun heats surfaces and the ground radiates that heat back into the air. It also changes with altitude: for every 1,000 m you climb, the air is roughly 6°C cooler.

Humidity tells us how much water vapour is in the air as a percentage of the maximum it could hold at that temperature. At 100% humidity, the air is saturated — water starts to condense as dew, fog or rain. Nepal's monsoon brings humidity levels above 80% for months at a time. High humidity makes hot temperatures feel even hotter because sweat cannot evaporate efficiently to cool the body.

Atmospheric pressure is the weight of the entire column of air above you pressing down. At sea level this is approximately 1,013 hPa (hectopascals). As you go higher, there is less air above you and pressure falls. This is why our sensor can estimate altitude from the pressure reading alone — the relationship between the two is described by the barometric formula, which we will explore in a later activity.

Procedure

  1. Open the HICS dashboard on your device and navigate to the Climate section.
  2. Record today's air temperature, humidity and pressure in your notebook.
  3. Step outside (or look out the window). Write three observations about the weather using only your senses — what you see, feel, hear.
  4. Return to the sensor readings. Can you match each observation to one of the three numbers?
  5. Record the sensor values again 15 minutes later. Have any changed? By how much?
  6. Sketch a simple table with columns: Location (Terai / Hills / Mountains), Expected Temperature, Expected Humidity, Expected Pressure. Fill in what you think the values might be for each region today.

Discussion

  1. If the temperature outside is 28°C and the humidity is 85%, how would you expect to feel? What about 28°C at 30% humidity?
  2. Why might farmers in Nepal care deeply about humidity levels in April and May?
  3. The pressure reading at our station is lower than 1,013 hPa. What does that tell us about where our station is located?

Worksheet

1. Record the three sensor readings right now. Temperature: ___ °C Humidity: ___ % Pressure: ___ hPa [3 marks]

Answer guide (for teachers)

Observational — accept any accurate reading. Check students are reading the correct units.

2. In your own words, explain what humidity means. Use an example from daily life in Nepal. [3 marks]

Answer guide (for teachers)

Should include the idea of water vapour in the air. Good examples: damp clothes taking longer to dry in monsoon, sweat not evaporating on a humid day, morning dew on fields.

3. If you travelled from Kathmandu (1,400 m) to a village at 3,000 m, would the pressure reading increase or decrease? Explain why. [2 marks]

Answer guide (for teachers)

Decrease — there is less air above you at higher altitude, so the weight of the air column pressing down is less.

4. List TWO ways that high humidity affects daily life in Nepal during the monsoon. [2 marks]

Answer guide (for teachers)

Accept any two reasonable answers: clothes stay damp, mould grows faster, heat feels more intense, crops receive adequate moisture, rivers flood, landslide risk increases.

Vocabulary

Temperature
A measure of the average kinetic energy of air molecules, expressed in degrees Celsius (°C).
Relative Humidity
The amount of water vapour in the air expressed as a percentage of the maximum possible at that temperature.
Atmospheric Pressure
The force exerted by the weight of the air column above a point, measured in hectopascals (hPa).
Climate Zone
A region with a broadly consistent pattern of temperature, rainfall and seasonal change.

Extension

Research Nepal's five development regions and find the average annual temperature and rainfall for one location in each. Create a comparison table and write a paragraph explaining how altitude drives these differences.

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