Use fun activities to teach preschoolers how thermometers tell us the temperature. Show students how to read a thermometer and help them understand why knowing the temperature is important to everyday activities. Use visual aids, such as different styles of thermometers, along with brightly colored props, including photos and clothing.
Read the Thermometer
Weather forecasters tell us what the current outside temperature is and predict what it will be at various points during the day. Show preschoolers how they can do some of that work themselves. Let them see what an outside thermometer looks like and talk about how to read it. Depending upon the type of thermometer, you will need to show students how to read the mercury or where to look for the digital reading. Show pictures of thermometers registering various temperatures. While preschoolers might have difficulty reading the exact number on a mercury thermometer, they should be able to understand that the higher the mercury level, the hotter the temperature. Explain that outdoor thermometers work similarly to those that doctors and parents use to tell if children are feverish.
Match the Temperature
Help children understand what the temperature number means by giving them examples. Tell them what the temperature was when they came to school that morning or when they went out for recess. Further their comprehension by holding up photos of locations, such as a snowy mountaintop or a sandy desert, and talk about average temperatures at those spots. Hold up a number card with a temperature on it, and ask students to match the temperature with the correct location.
Let kids match the temperature with the correct type of clothing. Call out a temperature, such as 40 degrees, then let kids sort through a pile of clothing to pick which clothes would be best. Since preschoolers now understand that 40 degrees is cold, they should pick mittens, a sweater, a hat or a jacket. Items such as sunglasses, a bathing suit and flip-flops would be inappropriate for that temperature. Ask preschoolers to use words that best describe the temperature: freezing, cold, cool, warm or hot.
Temperatures also are key to cooking foods. Tell the children that a recipe normally calls for a specific oven temperature. Warn preschoolers that the temperatures needed to cook food are very hot --- hotter than the hottest day they have ever felt. Give students examples of the hottest days in recorded history, then give examples of common oven temperatures for various foods.