Temperature is a measurement of heat energy and describes the degree of molecular activity. Since different substances have different molecular structures, equal amounts of heat applied to two different objects of equal mass usually results in one object getting hotter than the other. For example, a land surface becomes hotter than a water surface when equal amounts of heat are added to each. In Figure ‘A’, Q* indicates the heat which becomes sensible or measurable heat on land but in water becomes latent or stored heat. The sun’s radiation unevenly heats the Earth’s surface during the day, creating temperature and pressure differences that ultimately drive the Earth’s weather.