In the wake of a weekend storm system that brought measurable snowfall to all of central and southern Minnesota, and the adjacent areas of west central Wisconsin, a surge of Arctic air moved southward.
The core of the coldest air mass (that hadn't been felt across the Upper Midwest since the Winter of 1995-96) moved southward from Monday afternoon, January 28th, through Wednesday evening, January 30th. The center of the cold air mass moved across Minnesota the afternoon of Tuesday, January 29th where 850mb temperatures were around -38F. Although temperatures slowly modified above the surface past the afternoon of Tuesday, January 29th, the combination of very strong winds and temperatures in the teens and 20s below zero, wind chill values averaged between 45 and 59 degrees below zero from Tuesday afternoon, through Wednesday morning. Although wind speeds lowered on Wednesday, actual temperatures in the 20s and 30s below zero kept wind chill values below -35F through Thursday morning.
The coldest measured wind chill of -59F in west central Wisconsin was at the Menomonie airport.

Extreme Cold/Wind Chill in BARRON, WISCONSIN
From 29-JAN-19 16:00:00 to 31-JAN-19 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Several local weather sources measured wind chill values lower than -35F from Tuesday afternoon, through Thursday morning. The coldest wind chill was -57F at the Cumberland airport.

Extreme Cold/Wind Chill in CHIPPEWA, WISCONSIN
From 29-JAN-19 17:00:00 to 31-JAN-19 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Several local weather sources measured wind chill values lower than -35F from Tuesday afternoon, through Thursday morning. The coldest wind chill was -53F at the Eau Claire airport.

Extreme Cold/Wind Chill in DUNN, WISCONSIN
From 29-JAN-19 16:00:00 to 31-JAN-19 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Several local weather sources measured wind chill values lower than -35F from Tuesday afternoon, through Thursday morning. The coldest wind chill was -59F at the Menomonie airport.

Extreme Cold/Wind Chill in EAU CLAIRE, WISCONSIN
From 29-JAN-19 17:00:00 to 31-JAN-19 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Several local weather sources measured wind chill values lower than -35F from Tuesday afternoon, through Thursday morning. The coldest wind chill was -53F at the Eau Claire airport.

Extreme Cold/Wind Chill in PEPIN, WISCONSIN
From 29-JAN-19 17:00:00 to 31-JAN-19 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Several local weather sources measured wind chill values lower than -35F from Tuesday afternoon, through Thursday morning. The coldest wind chill was -52F.

Extreme Cold/Wind Chill in PIERCE, WISCONSIN
From 29-JAN-19 16:00:00 to 31-JAN-19 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Several local weather sources measured wind chill values lower than -35F from Tuesday afternoon, through Thursday morning. The coldest wind chill was -52F at the  Red Wing airport.

Extreme Cold/Wind Chill in POLK, WISCONSIN
From 29-JAN-19 15:00:00 to 31-JAN-19 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

Several local weather sources measured wind chill values lower than -35F from Tuesday afternoon, through Thursday morning. The coldest wind chill was -54F.

Extreme Cold/Wind Chill in RUSK, WISCONSIN
From 29-JAN-19 17:00:00 to 31-JAN-19 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Several local weather sources measured wind chill values lower than -35F from Tuesday afternoon, through Thursday morning. The coldest wind chill was -51F at the  Ladysmith airport.

Extreme Cold/Wind Chill in ST. CROIX, WISCONSIN
From 29-JAN-19 15:00:00 to 31-JAN-19 06:00:00 (CST-6)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Several local weather sources measured wind chill values lower than -35F from Tuesday afternoon, through Thursday morning. The coldest wind chill was -56F at the New Richmond airport.