Grade Levels: 7th, 8th,
Social Studies, and Math
Students should be able to:
Duration of Lesson:
- Describe changes in states
of matter, and the energy changes involved.
- Compare and contrast three
methods of heat transfer (conduction, radiation, and convection).
- Describe the major elements
of weather, including temperature, relative humidity, dew point, barometric
pressure, wind, and precipitation..
- Name the instruments used
to measure each of the elements of weather.
- Describe and use various
instruments to take measurements of weather parameters.
4 or 5 50 minute class periods
Technology Tools / Courseware:
- a classroom weather station
which includes instruments to measure temperature, relative humidity, barometric
pressure, and rainfall amounts. If a weather station is not available,
thermometers, a barometer, and a rainfall gauge can be used independently
to collect data.
- Thermometers which measure
- Clean, empty soup or coffee
- Ice and water
- cotton balls or cotton
- rubber bands or string
- weather station or instruments
to measure air temperature, barometric pressure, relative humidity, and rainfall
- If a weather station is
not available, teachers can use thermometers and a barometer to take measurements
of their own. The activity on Day 2 describes how to make a psychrometer
to find the relative humidity, and tables can be used to calculate the dew
- Before doing the activity
on Day 2, be sure you have permission to let the students go to the designated
areas to take temperature readings. Depending on your school situation,
you may want to keep the entire class together and go to a few locations
for the readings.
- A sample data table for
the students can be found at weatherdata.xls.
Teachers may edit this table to include only those items they wish the students
to keep records of before printing out copies for their students.
- While scientific data should
always be measured in SI units (i.e. oC, meters), I use oF,
inches of mercury, and inches of rainfall when teaching
about weather since these are the standards used in weather forecasting in
this country. This allows students to compare the data they collect
with historical data or data collected by other local weather stations.
- Before conducting the activities,
explain to students the importance of using care with thermometers, especially
if they contain mercury.
- Day 1
- You may wish to introduce
the topic of weather by asking students how weather affects their lives,
and why weather prediction is so important to us. (We actually have
TV and radio stations devoted entirely to 24 hour a day weather information.)
Discuss various occupations that are especially impacted by weather conditions
(farming, sports events, city and road maintenance, etc.) and also talk about
the effects of severe weather on various parts of the US and the world.
What major weather events have impacted their own lives or cities?
- Show students the weather
station, and explain to them that they will be taking readings from the weather
station every day for the next month or so. At the end of that time,
they will learn how to use Excel to prepare a table and several graphs of
their data. Then they will compare their readings to historical data,
or to other recent data taken in their area.
- Give them each a printed
copy of the weather data worksheet that they
will use to record their data. Explain why it is important for them
to take readings at approximately the same time each day.
- Proceed to take and record
that day's readings, showing students how to properly use the weather station.
Focus on explaining how to take each reading, rather than on what the individual
readings mean. Tell them the units that they will be using, and explain
why they will not use SI units in their measurements.
- You may wish to assign
individual students to take the readings at the designated time each day
and record them on the board, or somewhere convenient for all students to
see. Each student should put the day's readings on their own
worksheets. Every student should have the opportunity to take the readings
at some point during the recording period.
- Day 2
- After recording the day's
readings, the teacher will use a lecture / discussion / activity format to
begin teaching students about phase changes and methods of energy transfer.
Explain that both concepts are important in understanding weather phenomena.
- Hand out the worksheet
on phase changes, or use the board or overhead
to present the information. Explain to the students that as they study
weather they will need to understand how energy (heat) affects the changes
in state of matter (of water, especially), as well as the density and volume
of water as it changes states. Point out that the evaporation and condensation
points are at the same temperature, as are the melting and freezing points.
- Next, use the handout on Heat Transfer. Explain the three ways
that thermal energy can be transferred. Have students do the brief
exercise at the bottom of the page to be sure that they understand the concepts.
These can be done in class or as a homework activity.
- Day 3
- Discuss the following elements
- instrument - thermometer
- units of measurement -
- should be placed 2 meters
above the ground in a location protected from rain, snow, or
- Relative Humidity:
- instrument - psychrometer
- units of measurement -
- relative humidity = (amount
of moisture in the air / amount of moisture the air can hold at that temperature)
x 100%. Explain that warmer air can hold more moisture (water vapor)
than cooler air, because the cooler the air, the more condensation will take
place, removing water vapor from the air. Warmer air holds more moisture
because the water vapor will evaporate into the air.
- Activity - Measuring
Divide students into teams of 2 to 4 students each. Each team will
need two thermometers, a cotton ball and rubber band or piece of string, or
a cotton shoestring, and a small square of cardboard (approximately 4 inches
square). The cotton ball or shoestring should be moistened with room
temperature water, and attached to the ball of one of the thermometers.
This is the wet bulb thermometer. Each team should select a different
location in the school (such as the gym, locker room, classroom, computer
lab, office, hallways, rest rooms, outdoors, etc.). They will go to
that location, and take and record two readings. First they will measure
the temperature with the dry bulb thermometer. Then they will fan the
dampened cotton ball with the cardboard until the temperature on the wet
bulb thermometer stops dropping (about 2 minutes). They will record
this second temperature, then return to their classroom with the data they
collected. Remind students that evaporation requires an increase in
energy. Therefore, as the moisture evaporates from the moistened cotton
ball or shoestring, it takes energy away from the bulb of the thermometer,
cause its temperature to drop. Upon returning, they will use the relative
humidity tables to determine the relative humidity of the location they tested.
If these tables are not available in their texts, students can use the weather calculator
on the NOAA website. They should then record their data on
the board for other students to see. Follow up with a brief discussion
of why the humidity might be different in different locations, and whether
the results were as expected.
- Day 4
- Begin by reminding students
to record their readings from the weather station. Review results of
previous day's activity if there was not time to finish. Continue lecture
/ discussion / activity as shown below.
- Dew Point:
- instrument - none; this
is a calculated value using temperature and relative humidity
- units of measurement -
- the temperature at which
dew (or frost) will form; the temperature at which the relative humidity
reaches 100%, and water vapor condenses out of the air. The dew point
depends upon the air temperature, since air at different temperatures can
hold different amounts of moisture before becoming saturated. Also,
if the dew point is below 32oF, then frost will form instead of
dew if the dew point is reached.
- Activity - Finding the
This can be done in groups, or as a demonstration by the teacher. Fill
an aluminum can with room temperature water, and observe the temperature.
Then slowly add ice to the water, stirring gently. Observe the temperature
on the thermometer as it drops. When condensation appears on the outside
of the can, note the temperature of the water. This is the dew point.
The air around the can was warmer than the water in the can. This caused
the air around the can to cool until it reached its dew point, resulting
- Barometric Pressure
Here's why. (The
students should understand these concepts!)
- Instrument - barometer
- Units - mm Hg (mercury),
inches Hg, or millibars. We will use inches of Hg.
- The pressure (weight per
unit area) of a column of air above the ground.
- High Pressure (H for Happy)
means fair weather.
Low Pressure (L for Lousy) means clouds and / or precipitation.
- Explain that changes in barometric
pressure are more significant than the current pressure readings. Rising
pressure means fair weather is on the way. Falling pressures predict
bad weather coming.
High pressure means the air must be more dense or heavier than surrounding
air, so it tends to sink. Sinking air warms as it gets nearer to the
Earth's surface. As it warms, it can hold more moisture. Therefore,
moisture in the air evaporates, so no clouds or precipitation forms.
Low pressure means the air must be less dense, or lighter, than surrounding
air, so it tends to rise. As it rises, it cools. But cool air
cannot hold as much moisture, so the water vapor in the air begins to condense,
forming clouds and possibly precipitation.
- Wind (direction and
- results from the differences
in barometric pressures across a region. Air tends to flow from regions
of high pressure to regions of low pressure.
- direction - measured
using a wind vane; wind direction always refers to the direction the wind
is blowing FROM.
- speed - measured
using an anemometer; units are in miles per hour or in knots.
- Day 5
- Look at the data that students
have been collecting from the weather station to see that they collecting
all the data they need. Remind them to continue taking readings for
the next several weeks. They will use the data to prepare tables and
graphs using Excel when they are done. Direct them to look at the barometric
pressure readings. Have they been changing throughout the week?
Do higher readings correspond to sunny days and lower readings to cloudy
or rainy days?
- Review the information
on phase changes, heat transfer, and the elements of weather (temperature,
relative humidity, dew point, barometric pressure, and wind). Tell
them that they will be taking a short quiz to
show that they understand the concepts that have been presented so far.
Have them work on the review sheet individually
before going over it together. Alternatively, it may be assigned for
- In the activity on day 2,
some students may be unable to move easily about the school to take readings.
Have these students take humidity readings in the classroom you are working
- If the weather station
is not in an easily accessible location, make sure that students unable to
take readings on their own get the data from classmates, and understand what
the measurements represent.
Evaluation / Assessment:
- While the students are taking
their daily readings from the weather station, you might have them use the
internet to keep a similar table that contains readings from their local
news stations or weather channels. These values could be graphed at
the end and compared to the readings taken by the students.
- Alternatively, the students
could use the internet to retrieve historical data or averages for each day
in their recording period. These average values could be graphed alongside
their actual data for comparison at the end of this unit.
- Using the internet, have
students try to find sites that show them the various cloud types.
Have them list the suffixes and prefixes for cloud names and tell what they
mean (i.e. nimbus, cumulus, stratus, etc.) Ask them to write a brief
summary of the cloud types they can identify.
State and National Standards:
- Quiz on the elements of
weather, heat transfer and phase changes.
West Virginia Standards:
Science: SC.7.2.1, SC.7.2.2, SC.7.2.3, SC.7.2.4, SC.7.2.5, SC.7.2.6,
SC.7.2.7, SC.7.2.8, SC.7.4.17,
SC.7.4.18, SC.8.2.1, SC.8.2.2, SC.8.2.3, SC.8.2.4, SC.8.2.5, SC.8.2.6, SC.8.2.7,
SC.9.2.2, SC.9.2.3, SC.9.2.4, SC.9.2.5, SC.9.2.6, SC.9.2.7, SC.9.2.8, SC.9.4.27
Social Studies: SS.8.4.11
Math: MA.7.15, MA.7.17
Science: Understands atmospheric processes and the water cycle.
Geography: Understands the characteristics and uses of maps,
globes, and other geographic tools and technologies.
Math: Understands and applies basic and advanced concepts of
statistics and data analysis.
Job / Career Clusters:
Science and Technology
Debbie Messenger, Clare McCarty,
St. Joseph Central Catholic High School