This document discusses how various weather elements are measured, including: - Rainfall is measured using a rain gauge in millimeters. - Temperature is measured using a thermometer in degrees Celsius or Fahrenheit. - Wind speed is measured using an anemometer and wind direction is measured using a wind vane. - Air pressure is measured using a barometer. It also mentions that students will keep a weather diary to record measurements from instruments in the school garden.

1. Weather and Climate
Lesson 2
How do we measure the
weather?
Wednesday 18th January 2012

2. Lesson Objectives
• To know the names of weather
instruments
• To understand the units they are
measured in
• To use the instruments to record the
weather!

3. p.7 What is the difference between weather and climate?
Weather is the day to day changes in the atmosphere.
temperature precipitation
wind speed humidity
wind direction cloud cover
air pressure sunshine

4. Rainfall p.8
Rain is a type of precipitation.
Precipitation is where water vapour in the air is cooled and condenses into water
droplets.
Other types of precipitation are snow, sleet, hail, dew or fog.
How is rainfall measured?
Rainfall is measured with a rain gauge.
rain gauge

5. Temperature p.8
Temperature is how hot or cold it is.
How is temperature measured?
Temperature can be measured using a thermometer such as
the liquid-in-glass type, where the liquid (mercury or spirit)
in the bulb expands and rises up a capillary tube.
Temperature is measured in either oCelsius or oFahrenheit.
Temperatures are measured in the shade, so that the heat of
the sun does not heat up the instrument being used.
Thermometer

6. Wind p.8
Wind is simply moving air.
Wind speed is how fast the air is moving.
How is wind speed measured?
Wind speed is measured by an anemometer. This
has metal cups which rotate in the wind.
The stronger the wind, the faster the anemometer
turns.
anemometer

7. Wind direction p.8
How is wind direction measured?
Wind direction is measured using a wind vane.
In this case, the wind has come from the north.
It is a northerly wind.
the arrow points
into the wind
See if you can spot a wind vane in your local
area.

8. Beaufort scale
How is wind speed estimated without an anemometer?
The Beaufort scale measures wind intensity using the
effects of wind to estimate its speed.
It uses a scale
from 0 to 12.
0 on the scale means
there is no wind.
12 indicates
hurricane
conditions.

9. Air pressure p.8
Air pressure is the force exerted on the Earth by the
weight of the air above.
How is air pressure measured?
It is measured with a barometer (or a barograph).

10. Weather instruments p.8

11. Which instrument? p.8

12. 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.

14. Cloud Cover
• Your eyes are the
most useful tools to
measure the
weather
• You can look at the
sky and see how
much is covered in
cloud
• We record this in
Oktas
• 1 Okta is ⅛th
• A full sky of cloud
would be 8 Oktas

15. Cloud type

16. Weather Diary
• As a class you have to keep a weather
diary for Canbury School
• In the garden a weather station has
been set up
• Lets go outside and have a look

18. Pg 44

19. • Record what day you have to observe
the weather at Canbury
– Wednesday – EVERYONE
– Thursday –
– Friday –
– Monday –
– Tuesday –
• There is a clipboard in class to take out
and then you must fill in the class diary