Part 1: How does the weather change?
For this section, you can have the students answer the questions individually or in small groups. Alternatively, you can lead a whole class discussion and elicit ideas from students and write responses on a chart or blackboard. You can use all or some of the questions provided in the first part of the student activity. After some time, ask the students to suggest various ways to analyze the data they've collected in the field. Write responses on the chalkboard. Ask students to discuss how the class might undertake each response.

Part 2: Weather Variables
For this exercise, students will graph several of the weather variables to later, in Part 3, look for trends and relationships.

1. Temperature: Students will draw three separate line graphs for each of the three cities comparing the temperature in ºC over time. Since line graphs show gradual changes in data, students will be able to quickly determine if the temperature rose, fell, or stayed the same over the two-week period. An example of the types of line graph produced in this activity has been constructed and is available below, however this is NOT the same data that students will use in their activity so their graph will be different from the example.
   • Sample temperature over time line graph
2. Wind Direction: Students should label the Wind direction from each day for each of the cities at the same points for the temperature for each day using the same temperature over time line graphs.
3. Sky Conditions: Students will draw three separate circle graphs to compare the observed sky conditions (sunny, cloudy and rainy days) from each of the three cities. To categorize the different sky conditions into three discrete categories, students will need to combine certain conditions. For example, students may select to combine all days with clouds as "cloudy days". As another option, students can break the circle graphs into more or less parts. An example of the types of circle graph produced in this activity has been constructed and is available below, however as in the previous case, this is NOT the same data that students will use in their activity so their graphs will be different:
   • Sample sky conditions circle graph
4. Precipitation: Students should draw a BAR graph comparing the precipitation each day over time. If there is no precipitation recorded during the two-week period, students should record 0 for each of the days. The most important thing for this activity is that they learn how bar graphs are good for comparing data and illustrating how something changes over time.
   • Sample comparison precipitation bar graph
5. Air Pressure: Students should draw three separate line graphs similar to the graphs they drew for temperature however they should label the y-axis in mb from the lowest to the highest recorded air pressure value. For example, if the lowest recorded value was 997 mb, they should begin their graph at or about 995 mb.

Part 3: Analyze the Data
Students should use the graphs as the basis for their answers in this section. Since each participating class will be recording the weather over different periods of time of the year and each class is located in a different city, it is not possible to create an answer key. However since all of the students will have recorded the weather variables over the same period of time, their answers should be the same with a few exceptions noted below.

1. Temperature: Students should also answer each question for each of the three locations. Students will also need to calculate the average high temperature in each location.
2. Sky Conditions and Temperature:
   1. Students should also answer each question for each of the three locations.
   2. The trend that the students should begin to notice is that generally, the temperature should be lower, or colder on cloudy or stormy days and higher, or warmer on sunny days. This is because clouds and stormy conditions block the sun's rays from warming the earth's surface, and therefore result in colder temperatures.
3. Wind Direction and Temperature: Wind is the result of a difference in air pressure and is caused by the unequal heating of the Earth's surfaces.
   1. Students should also answer each question for each of the three locations.
   2. Wind has different effects on weather depending on geographic location. Generally, the wind blowing from one direction will bring colder air while the wind blowing from a different direction will bring warmer temperatures. For example, in the northern latitudes around the United States, wind blowing from the north brings colder air while wind coming from the south generally has the adverse effect. To see the current wind direction and speed, view the following links:
      • Canada
      • United States
      • Mexico
      • Central America
      • South America
4. Precipitation: Students should also answer each question for each of the three locations. Students will also need to calculate the total precipitation in each location.
5. Air Pressure and Sky Conditions: Air pressure is one of the key indicators of future weather conditions. This is because air is compressed in a high pressure area and warms as it descends, and the resulting warming inhibits the formation of clouds. In other words, this means that the sky is normally sunny in a high-pressure area, however fog and haze may still form. In a low air pressure are, just the opposite occurs.
   1. Students should also answer each question for each of the three locations.
   2. In general, students should notice that falling or decreasing air pressure leads to cloudy weather and raising air pressure leads to sunny days and fairer weather (NOTE: This will not apply at all latitudes).