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Weather Watchers

  • Lesson
Data Analysis and Probability
Location: Unknown

Students collect and analyze data about the weather and learn to make a stem-and-leaf plot. Students use newspapers, the Internet, or other sources to collect weather data.

This lesson was adapted from "Finding Our Top Speed", as found in Mission Mathematics II: Grades 6–8, a joint NASA/NCTM project, NCTM 2005.

NASA scientists gather and use weather data to discover possible long- and short-term climate changes. By taking measurements in space and on the ground, they can decide if a connection exists between what is happening in the atmosphere and in space.

NASA and the National Oceanic and Atmospheric Administration (NOAA) supply local news programs with information for the weather reports. Managed by the NASA Goddard Space Flight Center in Greenbelt, Maryland, the Earth Observing System (EOS) includes a series of polar-orbiting and low-inclination satellites that observe and record information about the land surface, biosphere, solid Earth, atmosphere, and oceans.

In this activity, students act as NASA scientists by collecting data to help them predict the weather.

Weather satellites are important for collecting data about Earth. These unmanned spacecraft carry a variety of sensory equipment that scans Earth and electronically communicates the data back to scientists on Earth.

1033 satellite

Getting Started

Pose the following question to students:

Why do scientists keep data about the weather by recording such measurements as temperature, precipitation, and barometric pressure?

Students should discuss implications of weather data, such as climate changes, as developmentally appropriate.

Developing The Activity

Tell students that they will be collecting their own data so that they can summarize their findings and make predictions about the weather in their area. Every day for thirty days, students will collect high and low temperatures.

Pose the following questions to students:

  • How can we collect weather data? What are sources for weather information? [Our own observations and measurements, newspapers, nightly news shows, the Internet, or radio programs.]
  • How can we make an easy-to-understand record of our data? [Table, spreadsheet, etc.]
  • Should everyone collect the same data, or should some groups specialize in different measures?

Encourage suggestions from your students. Students can work in small groups to design a data-recording sheet. You may want to direct all groups to collect high and low daily temperatures. Each group, however, could decide what other data to collect, such as wind direction and speed, times of sunrise and sunset, barometric pressure, and humidity.

Students should record their data for thirty days. You may want to have a regular time during the week to talk about patterns that students see in their data.

After thirty days, have students work in their groups to decide how to display their data. Ask them to share their ideas with the whole class.

Some different ways that students may choose follow:

  • A single- or multiple-line graph to show how the selected data change form day to day across the thirty-day period
  • A line plot to show the number of days that given conditions were present
  • A stem-and-leaf plot to show frequencies for intervals of temperatures
  • A double-bar graph to compare daily high and low temperatures across a given period, such as a week

Sample Line Plot for Daily High Temperatures 

1130 temps 

Pose the following questions to students:

  • What can you tell me about your graphs?
  • If we continue to collect data in the same way, would your graphs look the same next month? Why or why not?
  • How will the graphs help us predict weather for the same time next year?
  • Why is it important that we try to predict the weather?
  • Why would the scientists and engineers at NASA be interested in collecting data about the weather?

Stem-and-Leaf Plots  

You may want to use the students­ data to introduce or review the use of a stem-and-leaf plot. As you record data in this type of graph, ask students to observe the process and to describe how you have organized the data.

Write the following set of daily high temperatures on an overhead transparency or on chart paper for the students to see. You may want to substitute a student­s data set in this graphing activity if one is available.

1033 30 day temps

As you record each leaf value in a row of data, cross off the corresponding data point from the original set of data. For example, in the first row of the stem-and-leaf plot, as you record the 4, cross off the 64 in the given data set. As you record the 7 in the first row, cross off the 67. As you record the 8, cross off the 68. As you record the 9, cross off the 69.

1033 stems leaves

Use the Questions for Students (below) to discuss the stem-and-leaf plot.

Closing The Activity

Ask students to create their own stem-and-leaf plots using the class data. They can work together in their groups to help one another. Plan time for them to share their data and graphs with their classmates. Ask questions to help them identify patterns and think about predictions for the next week.

  • Newspapers, Internet sites (such as the National Oceanic & Atmospheric Administration), or other sources of weather data 



Assessment Option 

As you plan assessment for this activity, consider how the assessment offers opportunities for students to evaluate, reflect on, and improve their own work - to become independent learners. You may want to ask students to:

  • Write a paragraph to summarize their findings from their data and share the paragraphs with partners.
  • Explain why it is important to keep weather data from year to year.


  1. Ask students to keep a journal or record of the predicted weather, using a local newspaper or news program. Compare that data with data they collect. Are the meteorologists always right? What factors affect the meteorologists' accuracy?
  2. As students become more proficient with the stem-and-leaf plot, you may want to introduce a back-to-back stem-and-leaf plot. For example, students can plot both the high and low temperatures for the thirty days by having a center column for the stems, a left column for the leaves of the low temperatures, and a right column for the leaves of the high temperatures.

Questions for Students 

1. Why do you think that this graph is called a stem-and-leaf plot? What numbers are the stems? What numbers are the leaves?

[The graph may resemble a tree or a plant. The tens place value is represented by the stem, and the ones place value is represented by the leaf.]

2. How does this graph help us "see" the data better?

[You can see the data by the tens place value.]

3. Is this the best way to organize the data? Why or why not?

[Student responses may vary. Students may suggest scatter plots or tally charts as alternatives.]

4. What other data could we organize in this way?

[Student responses may vary; students may say heights (in inches), test scores, and other numerical data.]

Learning Objectives

Students will:

  • Collect, organize, and describe weather data.
  • Construct, read, and interpret different displays of data, such as line graphs, line plots, and stem-and-leaf plots.
  • Formulate and solve problems that involve collecting and analyzing data.

NCTM Standards and Expectations

  • Collect data using observations, surveys, and experiments.
  • Represent data using tables and graphs such as line plots, bar graphs, and line graphs.
  • Describe the shape and important features of a set of data and compare related data sets, with an emphasis on how the data are distributed.