1. Rainfall

4. Rainfall
Rain is a type of precipitation.
Precipitation occurs when water
vapour in the air cools and
condenses into water droplets.
How is rainfall measured?
Rainfall is measured using a
rain gauge.
Rainfall is usually measured in
millimetres (mm).
Snow, sleet, hail, dew and fog
are also types of precipitation.

6. Can you recall
how to draw and
label the different
parts of the rain
gauge?

7. Where should the rain gauge be place?
• In an open area / field
– So that nothing will
block the rain from
being collected in the
rain gauge.

8. Where should the rain gauge be place?
• A rain gauge should not be place near
trees.
– So that excess water collected from the leaves
will not drip into the rain gauge making reading
inaccurate .

9. Where should the rain gauge be place?
• A rain gauge should not be place near
buildings.
– So that excess water from the rooftop will not
drip into the rain gauge making reading
inaccurate .
– The building could also radiate heat causing
the water collected to evaporate.

10. Where should the rain gauge be place?
• It should be partially
buried in the ground
– to prevent it from being
topple.

11. Where should the rain gauge be place?
• It should be placed 30
cm above the ground
– to prevent rain splash
entering the rain gauge
making the reading
inaccurate.

12. High tech weather instruments

14. Isohyets
• a line on a
map
connecting
places
having equal
rainfall

17. Climograph
• It is a graph that shows
the monthly precipitation
and temperature
conditions for a selected
place.
• Precipitation is shown by
the bar graph.
• A line graph shows
temperature.

18. • What is the rainfall
for the month of July?
• Which month
experiences the
highest temperature?
• What is the
temperature range
for the whole year?
• What is the average
precipitation from
May to July?