Temperature
Temperature is the measure of hotness or coldness of an object. Temperature can be measured in metric units or in U.S. customary units. We can use a thermometer that has both a Celsius ( $\xb0C$ ) and a Fahrenheit ( $\xb0F$ ) scale to measure the temperature.
The following table shows the different temperatures on Celsius ( $\xb0C$ ) and a Fahrenheit ( $\xb0F$ ) .
Temperature

Fahrenheit (
$\xb0F$
)

Celsius (
$\xb0C$
)

Normal Human Body Temperature  $98\xb0F$  $37\xb0C$ 
Room Temperature  $68\xb0F$  $20\xb0C$ 
Water Boils  $212\xb0F$  $100\xb0C$ 
Water Freezes  $32\xb0F$  $0\xb0C$ 
Metric Units
In metric unit, temperature is measured in degrees Celsius ( $\xb0C$ ). The Celsius scale is also called the centigrade scale since it's divided into $100$ degrees. The Swedish astronomer Anders Celsius who developed Celsius temperature scale.
U.S. Customary Units
In the customary unit, temperature is measured in degrees Fahrenheit ( $\xb0F$ ). The physicist Gabriel Daniel Fahrenheit who named Fahrenheit ( $\xb0F$ ) in $1724$ .
The thermometers on the above figure show the water freezes at $0\xb0C$ or $32\xb0F$ and boils at $100\xb0C$ or $212\xb0F$ .
To convert temperatures from Fahrenheit to Celsius, use the formula $C=\frac{5}{9}(F32)$ and for Celsius to Fahrenheit is $F=\frac{9}{5}C+32$ .
For Example, the lowest recorded temperature in Oklahoma is $31\xb0F$ on February $9$ , $2011$ . Find the temperature in degree Celsius.
The expression to convert a temperature in Fahrenheit to degree Celsius is $C=\frac{5}{9}(F32)$ .
To convert $31\xb0F$ to degree Celsius, first replace $F$ with $31$ .
$\begin{array}{l}\frac{5}{9}(F32)=\frac{5}{9}(3132)\\ =\frac{5}{9}(63)\end{array}$
Next, multiply.
$\frac{5(63)}{9}=\frac{315}{9}$
Now, divide.
$=35$
Therefore, the temperature in degrees Celsius is $35\xb0C$ .
Note : The Kelvin( $K$ ), a unit of thermodynamic temperature, is the $\frac{1}{273.16}$ of the absolute temperature of the triple point of water.