While Iowans are enjoying unseasonably warm weather this October, they can expect a colder than normal upcoming winter. State Climatologist Harry Hillaker is basing that prediction on the cool conditions in the tropical Pacific — an indicator of a La Nina event, which tends to bring below normal temps to the Midwest.
“The tendency for the mid-winter months – January, February and March – is colder than usual when La Nina’s around,” Hillaker said. The same La Nina event helped forecasters accurately predict warmer than normal conditions this summer and fall. Hillaker says precipitation is more difficult to predict, but he’s betting on a relatively snowy winter.
“Which would not be much of a change from what the last several winters have been like,” Hillaker said. “We’ve already had three colder than normal winters in a row in Iowa and four snowier than usual winters in a row.” Last winter was particularly bad with several blizzards and persistently cold temperatures that kept a deep snow cover in place from mid-December through March.
“Overall, it ranked as our sixth snowiest winter on record in Iowa,” Hillaker said of the 2009-10 winter season. “One thing that was really unusual about the winter is it just never got very warm.” It was the 21st coldest winter on record, with a statewide average temperature of 17.5 degrees. Iowans won’t have to worry about breaking out parkas and snow boots anytime soon. High temperatures this week across most of the state are expected in the 60s to lower 70s.