This document discusses how weather is measured and defined. It explains that weather involves measuring temperature, precipitation, sunshine, air pressure, wind, and cloud cover. Various instruments are used like thermometers, rain gauges, and barometers. Climate is the average weather conditions over time for a region. The document then discusses factors that influence Texas weather like air masses, distance from the equator, and elevation. Climate graphs are introduced which show average monthly rainfall and temperatures on bar and line graphs. An example climate graph is provided for San Antonio.

2. Contents
• The Weather Forecast.
• What is Weather?
• How do we Measure Weather?
• What Affects Texas’ Weather and Climate?
• Climate Graphs.

3. The Weather Forecast!
• Most people watch the weather forecast
everyday – but do we really know how
they gather all the information?!

4. What is weather?
• Weather is:

5. What is climate?
• Climate is:
Scotland!

6. How do we measure weather?

7. Temperature
• Air temperature is measured
using maximum - minimum
thermometers.
• Q: What would the
temperatures be on this
thermometer?
A: Minimum = 6°C, Maximum = 18°C

8. Temperature.
• Thermometers are housed in a
Stevenson Screen. These are
always off the ground and
painted white!
Q: Why are thermometers kept
there? Why is it white?
A: It provides shelter from wind, rain, snow
and animals. The white colour reflects the
sunlight so heat doesn’t build up inside the
box.

9. Precipitation.
• Precipitation is any
moisture that comes
from the atmosphere
(rain, snow, hail).
• The amount of
precipitation is
measured using a
rain gauge.
Q: Where do you think would be best to place a rain
gauge? Beside a building or in an open space?

10. Sunshine hours.
Sunshine
Glass Ball
• The total amount of
sunshine in a day
is measured using
a sunshine
recorder.
• The sun’s rays
travel through the
glass ball and burn
marks onto the
Strip of
card behind it.
card

11. Air Pressure.
• Air pressure is
measured using a
barometer and
recorded using a
barograph.
• It is measured in
millibars (mb).
Barometer
Barograph

12. Wind.
Wind is measured in two ways with two instruments:
1. Wind Direction – Wind Vane
2. Wind Speed – Anemometer
Wind Vane: the arrow
points in the direction that
the wind is coming from.
Anemometer: the stronger the
wind the faster the caps turn.
The number of turns in a given
time gives us the wind speed in
knots.

13. Cloud cover.
• Cloud cover is measured
just by using our eyes.
• You look at the sky and
decide how cloudy it is –
and estimate how many
eighths of the sky are
covered.
• Cloud cover is measured in
oktas.

14. The Different Types of Clouds

15. What affects Texas’ Weather &
Climate?
• Air Masses
• Distance from
Equator
• Elevation

16. Air Masses
• The Continental
Tropical and the
Maritime Tropical air
masses most impact
Texas weather and
climate

17. Distance from Equator
Equator
The further in land you go the hotter it gets in the
Summer and the colder it gets in the Winter!
What do you notice about all the places
along the dotted line?

18. Elevation
• The higher the land,
the colder the air
temperature.

19. Elevation
• In the very western part of Texas, there are mountains
San
Antonio

20. Climate Graphs.
• Climate graphs
show two different
things – average
monthly rainfall
& average
monthly
temperatures.
• How do you
draw a climate
graph?

21. Weather Data

22. A bar-chart is drawn to
show the average monthly
rainfall.
A line graph is then added to
show average monthly
temperatures.
Months
Rainfall (mm)
Temperature
(°C)
Drawing a climate graph.

23. Draw a climate graph!
What would climate charts for San Antonio look like?
San Antonio Average Monthly Temperature
Jan
Average Temperature
Feb
Mar
Apr
May
Jun
Jul
Aug
Sep
Oct
Nov
Dec
49.2
53.8
61.7
69.3
75.5
82.2
85
84.9
79.3
70.2
60.4
52.2

24. Climate Graph for San Antonio

25. Climate Graph for Grand
Rapids, Michigan
Ja n
Average
Monthly
Temperature
Fe b
Ma r
Apr
Ma y
Ju n
Ju l
Aug
Sep
Oct
No v
De c
21.8
23.7
34.1
46
57.5
67
71.6
69.5
61
49.5
38
27.1

26. Review
•What is weather?
•In what ways is weather measured?
•What affects Texas’ weather and climate?
•What are climate graphs?