First of all - what is kinetic energy
Kinetic energy is the energy of motion.

Temperature - Temperature is the degree of hotness and coldness of the atmosphere and is measured either in degrees Celsius or degrees Fahrenheit. 

Molecules or atoms - Tiny pieces of matter.


Now, temperature denotes the amount of hotness or coldness of air - everything is made of molecules and atoms; so, is air. Air consists of numerous gas molecules.There is a law about molecules - as a matter gets hotter, the particles(referring to "atoms" and "molecules") inside it move faster and faster - and likewise, temperature cold, it goes vice-versa. So, if the temperature is hot, it indicates that the kinetic energy of molecules in air is high and if the temperature is cold, they move very slowly; so, it is like that - the movement varies from temperature to temperature.