Geography of Oklahoma - Climate

Climate

Oklahoma is situated in a temperate continental climate between regions of differing prevailing winds, making its weather widely different between relatively short distances. Much of the state is often subjected to extremes in temperature, wind, drought, and rainfall. Most of the state lies in an area known as Tornado Alley characterized by frequent interaction between cold and warm air masses producing severe weather. An average 54 tornadoes strike the state per year—one of the highest rates in the world. Because of its position between zones of differing prevailing temperature and winds, weather patterns within the state can vary widely between relatively short distances.

Eastern Oklahoma has a humid subtropical climate (Koppen Cfa) heavily influenced by southerly winds bringing moisture from the Gulf of Mexico and provides hot, humid summers and generally mild winters with cold spells. This transitions progressively to a semi-arid zone (Koppen BSk) in the high plains of the Panhandle, where a drier climate prevails with somewhat colder winters and similarly hot summers but much lower humidity. Other western areas of the state, including Lawton and Enid in the transition zone, are also less touched by southern moisture and tend to be drier. Precipitation and temperatures fall from east to west accordingly, with areas in the southeast averaging an annual temperature of 62 °F (17 °C) and an annual rainfall of 56 inches (1,420 mm), while areas of the panhandle average 58 °F (14 °C), with an annual rainfall under 17 inches (430 mm). All of the state frequently experiences temperatures above 100 °F (38 °C) or below 0 °F (−18 °C), and snowfall ranges from an average of less than 4 inches (10 cm) in the south to just over 20 inches (51 cm) on the border of Colorado in the panhandle. The state is home to the National Storm Prediction Center of the National Weather Service located at Norman.