Strong winds, which were slowly decreasing after a snowfall, combined with bitterly cold arctic air to drive wind chills to 35 to 50 degrees below zero from late on December 17th through the morning of December 18th.

Extreme Cold/Wind Chill in LYON, IOWA
From 17-DEC-16 15:00:00 to 18-DEC-16 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Law Enforcement

Strong northwest winds on December 17th, decreasing to around 10 mph during the night of the 17th, combined with falling temperatures to lower wind chill readings to 40 to 50 below zero. Actual temperatures dropped to colder than 20 below zero.

Extreme Cold/Wind Chill in OSCEOLA, IOWA
From 17-DEC-16 15:00:00 to 18-DEC-16 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Strong northwest winds on December 17th, decreasing to around 10 mph during the night of the 17th, combined with falling temperatures to lower wind chill readings to 40 to 50 below zero. Actual temperatures dropped to colder than 20 below zero.

Extreme Cold/Wind Chill in DICKINSON, IOWA
From 17-DEC-16 15:00:00 to 18-DEC-16 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Strong northwest winds on December 17th, decreasing to around 10 mph during the night of the 17th, combined with falling temperatures to lower wind chill readings to 40 to 50 below zero. Actual temperatures dropped to colder than 20 below zero.

Extreme Cold/Wind Chill in SIOUX, IOWA
From 17-DEC-16 15:00:00 to 18-DEC-16 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Strong northwest winds on December 17th, decreasing to around 10 mph during the night of the 17th, combined with falling temperatures to lower wind chill readings to 40 to 50 below zero. Actual temperatures dropped to colder than 20 below zero, including a record 26 below zero near Sioux Center.

Extreme Cold/Wind Chill in O'BRIEN, IOWA
From 17-DEC-16 15:00:00 to 18-DEC-16 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Strong northwest winds on December 17th, decreasing to around 10 mph during the night of the 17th, combined with falling temperatures to lower wind chill readings to 40 to 50 below zero. Actual temperatures dropped to colder than 20 below zero, including a record 26 below zero at Sheldon.

Extreme Cold/Wind Chill in BUENA VISTA, IOWA
From 17-DEC-16 15:00:00 to 18-DEC-16 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Strong northwest winds on December 17th, decreasing to around 10 mph during the night of the 17th, combined with falling temperatures to lower wind chill readings to 40 to 50 below zero. Actual temperatures dropped to colder than 20 below zero.

Extreme Cold/Wind Chill in CLAY, IOWA
From 17-DEC-16 15:00:00 to 18-DEC-16 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Strong northwest winds on December 17th, decreasing to around 10 mph during the night of the 17th, combined with falling temperatures to lower wind chill readings to 40 to 50 below zero. Actual temperatures dropped to colder than 20 below zero.

Extreme Cold/Wind Chill in PLYMOUTH, IOWA
From 17-DEC-16 16:00:00 to 18-DEC-16 10:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Strong northwest winds on December 17th, decreasing to around 10 mph during the night of the 17th, combined with falling temperatures to lower wind chill readings to 35 to 45 below zero. Actual temperatures dropped to colder than 20 below zero.

Extreme Cold/Wind Chill in CHEROKEE, IOWA
From 17-DEC-16 16:00:00 to 18-DEC-16 10:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Strong northwest winds on December 17th, decreasing to around 10 mph during the night of the 17th, combined with falling temperatures to lower wind chill readings to 35 to 45 below zero. Actual temperatures dropped to colder than 20 below zero.

Extreme Cold/Wind Chill in WOODBURY, IOWA
From 17-DEC-16 16:00:00 to 18-DEC-16 10:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Strong northwest winds on December 17th, decreasing to around 10 mph during the night of the 17th, combined with falling temperatures to lower wind chill readings to 35 to 45 below zero. Actual temperatures dropped to colder than 20 below zero, including a record 20 below zero at Sioux City.

Extreme Cold/Wind Chill in IDA, IOWA
From 17-DEC-16 16:00:00 to 18-DEC-16 10:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: COOP Observer

Strong northwest winds on December 17th, decreasing to around 10 mph during the night of the 17th, combined with falling temperatures to lower wind chill readings to 35 to 45 below zero. Actual temperatures dropped to around 20 below zero.