After some light to moderate snowfall the previous few days, Canadian high pressure moved southward into the Plains.  As the high pressure system progressed, surface winds increased over areas of Minnesota and Iowa, quickly ushering in colder temperatures and quickly falling wind chills.  By the afternoon and overnight hours of the 17th into the 18th, wind chills plummeted well below zero, approaching the negative 30 and 40 ranges through large portions of northern and central Iowa.

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

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

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

Extreme Cold/Wind Chill in WINNEBAGO, IOWA
From 17-DEC-16 21:00:00 to 18-DEC-16 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Extreme Cold/Wind Chill in HANCOCK, IOWA
From 17-DEC-16 21:00:00 to 18-DEC-16 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

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

Extreme Cold/Wind Chill in CERRO GORDO, IOWA
From 17-DEC-16 21:00:00 to 18-DEC-16 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Extreme Cold/Wind Chill in WORTH, IOWA
From 17-DEC-16 21:00:00 to 18-DEC-16 12:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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