Snowflakes, or more accurately, snow crystals form directly inside of clouds as the water vapor freezes into ice. They begin as a tiny speck of dust high in the sky. Crystals begin building on this speck as water vapor in the clouds comes in contact with it. The water vapor condenses and freezes directly onto it. As the crystal becomes heavier than the air around it, it will begin to fall to the ground. More water vapor in the air will add to the crystal as it falls, increasing the snowflake’s size. If the temperature is consistently below freezing while the crystal descends, it will land on the ground as snow. Sometimes water vapor will condense and begin to fall as liquid before freezing in the air on its descent. That is different from snow and is known as sleet.