Why Do Most Tornadoes Occur in the Late Afternoon?



Although they can occur at any time of the day or night, most tornadoes form in the late afternoon. By this time, the sun has heated the ground and the atmosphere, and the denser cold air is pushed over the warm air, usually producing supercell thunderstorms. Studies have shown that most tornadoes occur between 4-9 p.m., when the atmospheric conditions are most ripe. As for the time of year when tornadoes are most prevalent, May through September is tornado and hail season, with mid-June to early August being the peak time. Tornadoes that occur are night are the most dangerous because they are wrapped in heavy precipitation and can’t be seen. The best way to identify that a tornado is in the vicinity is by the loud continuous roar or rumble that doesn’t fade in a few seconds like thunder. Small, bright blue-green to white flashes at ground level near a thunderstorm, as opposed to silvery lightning up in the clouds, is also an indicator. Tornadoes at night only make up about 27% of all tornadoes, but are responsible for 39% of tornado deaths. Before a tornado strikes, the wind may die down and the air may become very still. An approaching cloud of debris, even if a funnel is not visible, also indicates a tornado. The state with the highest number of tornadoes is Oklahoma, followed by Kansas. The deadliest tornado on record was the Tri-State Tornado, which struck Missouri, Illinois and Indiana in 1925. The tornado was three-quarters of a mile wide and traveled a 219-mile path over a period of 3½ hours. It was an F5 tornado, with winds in excess of 300mph. Approximately 751 people were killed, more than 2,298 were injured, and damages were at least $1.4 billion, making it the deadliest tornado in U.S. history.