What is temperature a measure of?

Temperature is a measure of average kinetic energy.

Explanation:

when the temperature of gas is increased the average kinetic energy of gas molecules will increased and gas particles moves fast. Thus because of high velocity gas molecules colloid with each other and also with the wall of container. We can say that collision between gas molecules increased by increasing the temperature. The pressure will also goes to increase.

But when the temperature is decreased the kinetic energy of gas molecules goes to decrease and collision will also decreased because of smaller velocity of gas molecules. Thus slow moving particles exerted low pressure.

Temperature and pressure are also directly related to each other. When temperature is high pressure will also high and when temperature is low pressure will also low.

Temperature is a measure of molecular movement. So it's a measure of how fast molecules are moving. The more energy in a particle or the more energy in matter, the higher the temperature is going to be.