SIOUX CITY | Temperatures dipped to 24 below zero in Sioux City overnight Sunday, marking the city's coldest New Year's Eve on record.
Sunday night's low temperature surpassed a previous Dec. 31 record of 19 below zero set in 1968, according to the National Weather Service in Sioux Falls.
The first hours of 2018 continued what has been a stretch of brutally cold temperatures with even lower wind chills. Temperatures dipped below the zero mark early Saturday morning and are not expected to reach positive digits until Tuesday.
Wind chills dropped as low as the 40s below zero Sunday into Monday, as the area sat under a wind chill warning through noon.
A wind chill advisory for much of Siouxland was scheduled to begin 6 p.m. Monday and continue through 10 a.m. Tuesday.
Monday's high was expected to reach 3 below zero, then dip to 18 below zero overnight with wind chill values near 30 below. Such low wind chills are dangerous, capable of causing frostbite to exposed skin in as little as 10 minutes.
Jeff Chapman, a meteorologist with the National Weather Service in Sioux Falls, said the extreme cold temperatures have been caused by a large-scale flow of arctic air. He said a short-lived warm-up will come from a flow to the west Tuesday, bringing slightly warmer temperatures around 17 degrees.
But another arctic front will move across the area Tuesday night, setting up cold weather in the low double digits for the rest of the week.
"These will be more high temperatures down closer to 10 to 15 above, but still 10 to 15 degrees below normal," Chapman said.
Average temperatures for this time of year are around 30 degrees with a low of 10, he said.