Science and Technology K–6 · Year 1

A day of temperatures: morning, midday and afternoon readings

Earth and Space (NSW 2017); Science understanding, Earth and space sciences, and Science as a human endeavour (ACARA v9)

PracticalLow risk

The idea

Air keeps warming for hours after the sun is highest, so three readings from one shaded spot show a rise from morning to mid-afternoon rather than a peak at noon.

What you need

A digital thermometer with a probe on a lead, reading to 0.1 of a degree Celsius
A white louvred screen on a post over grass, with the thermometer bulb 1.2 m above the ground and the screen door facing south, at least twice as far from any building or tree as that building or tree is tall
A class chart: date, 9 am reading, 12 noon reading, 3 pm reading, sky (clear, part cloudy, overcast), rain
A clipboard, a pencil and the school clock or a tablet clock
A printout of the Bureau of Meteorology climate averages page for the nearest station, showing its mean 9 am and mean 3 pm temperatures month by month

How to do it

Set the screen up over grass with the bulb 1.2 m above the ground and the door facing south, well clear of walls and paths. The Bureau of Meteorology states all four of those conditions for measuring air temperature.
Open the screen at 9 am, wait one minute, read to 0.1 of a degree and close it again. Record the reading and the state of the sky.
Repeat at 12 noon and at 3 pm on the same day, in the same way, with the same reader.
Do this for five school days, recording the sky every time.
Subtract each day's 9 am reading from its 3 pm reading and write the rise in a fifth column.
Draw the five days as groups of three bars and ring the highest reading of the week.
Compare the five rises with the Bureau's long-term mean rise for this month at the nearest station, and say which days were unusual and what the sky was doing on those days.

What you should see

On most days the 3 pm reading is the highest of the three and the 9 am reading the lowest, because the ground goes on warming the air for hours after the sun is highest. The long-term figures give the size to expect. At Sydney (Observatory Hill), Bureau of Meteorology station 066062, the September mean 9 am temperature is 15.7 degrees Celsius and the September mean 3 pm temperature is 19.2 degrees Celsius, a rise of 3.5 degrees, and the annual means give the same 3.5 degrees (17.5 and 21.0). The rise is not the same all year at that station: the 3 pm mean stands 2.2 degrees above the 9 am mean in October, November and December, 2.3 degrees above it in January and 5.5 degrees above it in July. A class should expect its own five rises to be of that order, with an overcast or rainy day giving a much smaller rise and sometimes none at all. Three daytime readings cannot capture the whole daily swing: September at that station has a mean daily maximum of 20.1 degrees and a mean daily minimum of 11.1 degrees, a 9.0 degree swing, because the coldest hour comes near dawn before anyone arrives. The learner knows it worked when the 3 pm bar is the tallest on most of the five days and the days that break the pattern are the cloudy or wet ones on the chart.

What changes

What you change: the time of day (9 am, 12 noon, 3 pm) across five days
What you measure: air temperature in degrees Celsius
What you keep the same: the same thermometer in the same screen, 1.2 m above grass, door facing south
one minute's wait after opening the screen before every reading
the same reader, the same clock and the same chart
the sky recorded at every reading so cloudy days can be told apart

Common misconceptions

Each of these ideas is wrong, and the activity is a chance to test it.

The hottest time of day is 12 noon, when the sun is highest.
A thermometer lying in the sun shows how hot the air is.
The air is warmed straight from the sun rather than from the ground beneath it.
One day of readings is enough to show the daily pattern.

Safety card

Low riskLearners carry it out

Hazards

Sun exposure on the walk out to the screen three times a day
A glass thermometer breaking if it is knocked or dropped
Reaching above head height to open a screen

Controls

Hats and sunscreen, and readings that take about a minute each
A digital probe thermometer rather than glass
The screen mounted at a height the learners can open with both feet on the ground

Note

No chemicals and no heat. Record the activity on Primary School RiskAssess (riskassess.com.au).

Curriculum references

The NSW syllabus outcomes and Australian Curriculum v9 codes this activity supports. They are references, not a verified or complete curriculum alignment.

Science and Technology K-6 Syllabus (2017), NESA. Current syllabus; NESA's timeline is 2026 plan and prepare, 2027 start teaching the 2024 syllabus. Code read from the official syllabus document on 2026-09-22.ST1-10ES-S ST1-1WS-S
Science and Technology K-6 Syllabus (2024), NESA. Implementation from 2027, so this code describes the future syllabus. Code read from the outcomes page on 2026-09-22.ST1-SCI-01 ST1-PQU-01 ST1-DAT-01
Australian Curriculum v9AC9S1U02AC9S1H01AC9S1I01AC9S1I03AC9S1I04AC9S1I05AC9S1I06

Sources

The pages the author read to write this activity.

All Concept Studio activities