The climate of a region is defined as the typical pattern of temperature and precipitation through the year. Climate is described using the average of 30 years of weather data for a location. Temperature and precipitation, recorded each day by meteorologists, are averaged for each day of the year. This allows us to know what it is usually like in July or November in a particular location. The actual weather on any given day can be very different than the average. For example, if there is a winter storm moving through a region, temperatures will likely drop to below average for that time of year.
About climate zones
The climate zones included in this activity are loosely based on the Köppen Climate Classification System. While the Köppen system is much more complex and includes many subcategories, the five climates used in this activity are the main groups used by the Köppen system:
- A: Tropical
- B: Arid (called Dry in this activity)
- C: Temperate (called Mild in this activity)
- D: Continental (called Cool in this activity)
- E: Polar and Alpine (called Polar in this activity)
There are many climates within each of the five Köppen Climate groups and each has slightly different graphs of how temperature and precipitation vary through an average year. Specific locations will have slightly different climate graphs even if they are within the same climate zone. For the purposes of introducing elementary students to the five general climate groups, graphs used in this activity are based on the climate of the locations where Grandma traveled (Siberia, Egypt, Alaska, Spain, and Brazil) in Part 2 of the activity.
Reading climate graphs
A climate graph (also called a climograph) is used to describe how temperature and precipitation vary through the months of the year in a particular location. Typically, a climate graph is one graph that shows precipitation totals as a histogram (bar chart) and overlays temperature variations as a line graph. For simplicity, this activity introduces histograms of precipitation and line graphs of temperature on separate graphs. If you look up the climate graph for your location, you will likely find the two graphs combined. (Instructions for finding your local climate graph are in the Weather and Climate Data Exploration.)
Why are there variations in climate?
Latitude is the main reason that there are different climate zones around the world. Near the equator, temperatures are consistently warm throughout the year. In the polar regions, temperatures are colder. Between the equatorial regions and the poles, in the mid-latitudes, climates typically have strong seasonal differences.
How close an area is to an ocean also affects climate. Coastal areas in the mid-latitudes often have cooler summers and warmer winters than areas that are inland. The ocean also provides a source of moisture. Altitude also has an impact on climate, with high altitude locations having a cooler climate than lower elevations.
How do biomes relate to climate zones?
The types of plants that live in an area usually define biomes, which are large naturally-occurring groups of living things adapted to survive in a particular climate zone. For example, conifer forests called the taiga biome are characteristic of Cool Climate (Köppen Climate Zone D: Continental), while the broadleaf forest biome and grasslands are characteristic of Mild Climate (Köppen Climate Zone C: Temperate). The rainforest biome is characteristic of Tropical Climate, while the tundra biome is characteristic of Polar Climate. Have students look at the pictures on Grandma’s postcards to start a conversation about how biomes relate to climate zones.