That's when water vapor cools, forming clouds and then sometimes rain. The warmth of the sun turns water into tiny particles called water vapor. The line between two masses of air. A cold front is when cold air overtakes warm air, a warm front is when warm air overtakes cold air. In either case, you can get clouds or rain or storms.
Winds usually blow from areas of high pressure to areas of low pressure.
The amount of water vapor in the air. When the humidity is high on a hot day, your body can't cool itself down as fast, so it feels hotter. High clouds like cirrus are made completely of ice. Cumulonimbus are deep puffy grey clouds that produce thunderstorms, hail, and tornadoes. They sometimes climb forty to sixty thousand feet high.