The region has four distinct seasons. Spring is the wettest season and produces erratic severe weather ranging from tornadoes to winter storms. Summers are hot and humid, with only occasional and brief respite, and the humidity often makes the heat index rise to temperatures feeling well above . Fall is mild with lower humidity and can produce intermittent bouts of heavy rainfall, with the first snow flurries usually forming in late November. Winters are cold with periodic snow and temperatures often below freezing; however, thaws are usually frequent. Winter storm systems, such as Alberta clippers and Panhandle hooks, can bring days of heavy freezing rain, ice pellets, and snowfall.