# What is the SI unit of Temperature?

By BYJU'S Exam Prep

Updated on: September 25th, 2023

The SI unit of temperature is Kelvin. It is defined as by taking the fixed numerical value of the Boltzmann constant kB to be 1.380 649 × 10−23. The physical quantity that measures hotness or coldness in terms of any of several arbitrary scales is called Temperature. In most of countries, Kelvin is the primary unit of temperature for engineering and the physical sciences.

Table of content

## Answer: Kelvin is the SI unit of temperature.

The commonly used scale to measure the temperature is the Celsius scale (°C). It is an empirical scale in which 0°C is defined by the freezing point of water, and 100 °C is the boiling point of water, both at sea-level atmospheric pressure. As it has100-degree interval, hence it is called a centigrade scale.

### Effects of Temperature

Following are the physical processes that are related to temperature:

• the physical properties of materials including the solid, liquid, gaseous, or plasma, vapor pressure, electrical conductivity, density, solubility, hardness, wear resistance, resistance, strength thermal conductivity, and corrosion.

• The amount of thermal radiation emitted from the surface of an object.

• the rate and extent to which chemical reactions occur

• the speed of sound which is a function of the square root of the absolute temperature, etc.

Summary:

## What is the SI unit of Temperature?

The SI unit of temperature is Kelvin. It was developed by William Thomson and Baron Kelvin. This scale uses absolute zero as its null point.