False.
Rising air typically cools as it ascends through the atmosphere. This phenomenon is known as adiabatic cooling. As air rises, it encounters lower atmospheric pressure at higher altitudes, causing it to expand. When the air expands, it does work on its surroundings, which leads to a decrease in its temperature. As a result, rising air becomes cooler than the surrounding air at the same altitude.
Cooler air is denser than warmer air, so when air rises and cools, it can become more dense than the air around it. This can be an important factor in meteorology and atmospheric science, influencing the formation of clouds, weather patterns, and the dynamics of the atmosphere.