 1,100 tornadoes were reported region-wide in May from Texas to Minnesota and from West Virginia to Georgia. It's more than twice the 30-year average. One of the fiercest killed five people and injured dozens in rural Greenfield. ISU severe weather meteorologist and professor of meteorology William Gallus said extreme heat from a changing climate has increased ocean temperatures and is one contributing factor to this year's storms. Mexico and Texas were having record high temperatures.