Vertical movements of air are very important. When air rises, its pressure is reduced, causing it to expand. As a result, the air cools. As air cools, its ability to hold moisture decreases. When cooling air becomes saturated with moisture, clouds are formed.
Most clouds result from the upward movements of air masses.
Wind is air in motion. On a sunny day, warm air rising from land heatd by the sun flows toward the cooler water when the air sinks. The cooler air then rushes in toward land again to replace the warm air that is rising. This cycle continues as long as the daytime heating continues from the sun. Since air moves inland from the water, the wind is called a sea breeze.