While tornadoes can happen at any time of year, it's typically peak tornado season from March to June. This is because the weather is most ideal for severe storms and tornado formation at this time.
Tornadoes are caused by a clash of air masses. This occurs when cold air from Canada meets warm moist air from the Gulf of Mexico in the central United States. Known as "tornado alley" this area is home to many of the nation's most severe thunderstorms.
The Southern Plains of the United States, including Kansas and Oklahoma, sees the highest frequency of tornadoes from May through early June. This region is prone to tornadoes because warm, moist Gulf of Mexico air rises up rapidly over the flat plains without any barriers to slow it down.
A tornado is a violently rotating column of air that extends from a thunderstorm to the ground. It can last from one to two minutes and can cause significant damage.
To form a tornado, rain and lightning must be combined with strong winds. This is why tornadoes can occur almost anywhere in the country at any time of the year.
Most tornadoes occur between 3 and 9 p.m., but they can also happen anytime during the day or night. This “rule of thumb” doesn’t apply to all areas.
To determine how dangerous a tornado is, pay attention to its Enhanced Fujita Scale rating. This scale assigns a number to each tornado based on wind speeds and damage. It ranges from zero to five with a zero rating having three-second wind gusts of 65 to 85 mph and an EF5 tornado having wind gusts greater than 200 mph.