* Celsius (°C): This is the standard unit used in most of the world.

* Fahrenheit (°F): This is the standard unit used in the United States.

* Kelvin (K): This is the standard unit used in scientific contexts. It's an absolute temperature scale, meaning zero Kelvin represents the absolute absence of heat.

There are also some other, less common units:

* Rankine (°R): This is another absolute temperature scale, used primarily in engineering in the United States.

* Réaumur (°Ré): This scale was once widely used in Europe, but is now rarely used.

It's important to be aware of the unit being used when discussing or measuring temperature, as they can lead to very different values.