A tornado is a violent rotating column of air that extends from a thunderstorm to the ground. Tornadoes can vary in size and intensity, but most are around 500 feet wide and last less than 10 minutes. They are known for their strong winds, which can reach up to 300 miles per hour. Tornadoes can also cause significant damage to structures and can pick up and carry debris for miles. They are most common in the United States, but can occur in other parts of the world as well.