Centigrade is a temperature scale where water freezes at 0 degrees and boils at 100 degrees.

Scientists created the centigrade scale in the 1700s to have a measurement system based on something consistent and universal: the behavior of water. Today, scientists call it the Celsius scale after Anders Celsius, the Swedish astronomer who helped develop it, though many people still use both names.

Most countries around the world use centigrade for everyday temperature measurements. If you visit France or Japan or Brazil, you'll see weather forecasts in centigrade. A comfortable room sits around 20 degrees centigrade. A hot summer day might reach 35 degrees. When you have a fever, your body temperature rises above its normal 37 degrees Celsius.

The United States uses a different system called Fahrenheit for daily weather and cooking, where water freezes at 32 degrees and boils at 212 degrees. But American scientists use Celsius because it makes calculations simpler and lets them share data easily with researchers worldwide.