The very large and very cold arctic air mass from the Canadian Rockies from the day before lingered over entire region. With plenty of clearing skies, gusty winds easily resulted in wind chill values lower than 40 below zero for many northeast Montana locations.

Cold/Wind Chill in EASTERN ROOSEVELT, MONTANA
From 15-JAN-20 22:30:00 to 16-JAN-20 06:33:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Department of Highways

At the US-2 @Stateline DOT site (MTSTA), temperatures of -12 to -20 combined with wind speeds of 7 to 30 mph to create wind chill values of near -40 to -45 for about 8 hours from the late night of the 15th through the early morning of the 16th.

Cold/Wind Chill in WESTERN ROOSEVELT, MONTANA
From 15-JAN-20 20:18:00 to 16-JAN-20 06:30:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

At the Poplar airport mesonet site (KPO1), temperatures of -17 to -20 combined with wind speeds of 8 to 18 mph to create wind chill values of -40 to -44 for more than 7 hours from the late night of the 15th through the early morning of the 16th.  In addition, at the Poplar RAWS site (POPM8), temperatures of -16 to -23 combined with wind speeds of 9 to 27 mph to create wind chill values of -40 to -46 for about 10 hours from the evening of the 15th through the early morning of the 16th. Also, at the McDonalds MT-13 DOT site (MTMCD), temperatures of -14 to -21 combined with wind speeds of 9 to 26 mph to create wind chill values of -40 to -46 for almost 6 hours from the late night of the 15th through the early morning of the 16th.

Cold/Wind Chill in NORTHERN VALLEY, MONTANA
From 15-JAN-20 21:47:00 to 16-JAN-20 06:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

At the Glentana mesonet site (F2113), temperatures of -16 to -24 combined with wind speeds of 6 to 21 mph to create wind chill values of -40 to -45 for more than 8 hours from the night of the 15th through the early morning of the 16th. In addition, at the Bluff Creek RAWS site (BLUM8), temperatures of -22 to -25 combined with wind speeds of 9 to 14 mph to create wind chill values of -45 to -47 for more about 5 hours on the night of the 15th. Also at the Honrud mesonet site (E5606), temperatures of -17 to -19 combined with winds speeds of 8 to 23 mph to create wind chill values of near -40 to -42 for about 2 hours in the early morning of the 16th.

Cold/Wind Chill in RICHLAND, MONTANA
From 16-JAN-20 01:00:00 to 16-JAN-20 07:00:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

At the Sidney 201 AIRNOW mesonet site (A3696), temperatures of -16 to -22 combined with wind speeds of 10 to 15 mph to create wind chill values of -40 to -44 for 6 hours during the early morning of the 16th. In addition, at the Sioux Pass MT-16 DOT site (MTSOO), temperatures of -17 to -18 combined with wind speeds of 10 to 16 mph to create wind chill values of -40 to -42 for more than 3 hours during the early morning of the 16th.

Cold/Wind Chill in SHERIDAN, MONTANA
From 16-JAN-20 00:29:00 to 16-JAN-20 07:16:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

At the Comertown Turn-Off MT-5 DOT site (MTCOM), temperatures of -15 to -24 combined with wind speeds of 6 to 20 mph to create wind chill values of -40 to -47 for almost 7 hours through the early morning of 16th. In addition, at the Plentywood mesonet site (GGWPW), temperatures of -14 to -18 combined with wind speeds of 17 to 20 mph to create wind chill values of -40 to -44 for about 3 hours during the early morning of the 16th. Also, at the Medicine Lake RAWS site (MLKM8), temperatures of -17 to -22 combined with wind speeds of 10 to 19 mph to create wind chill values of -40 to -43 for about 4 hours in the early morning of the 16th.

Cold/Wind Chill in DANIELS, MONTANA
From 16-JAN-20 01:47:00 to 16-JAN-20 07:02:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

At the Navajo MT-5 DOT site (MTRED), temperatures of -18 to -24 combined with wind speeds of 6 to 17 mph to create wind chill values of -40 to -47 for about 5 and 1/2 hours during the early morning of the 16th. In addition, at the Scobey N MDA mesonet site (MTM78), temperatures of -16 to -19 combined with wind speeds of 12 to 24 mph to create wind chill values of -40 to -44 for almost 3 hours during the early morning of the 16th.

Cold/Wind Chill in MCCONE, MONTANA
From 15-JAN-20 23:50:00 to 16-JAN-20 06:50:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

At the Fort Peck Dam mesonet site (GGWFP), temperatures of -13 to -15 combined with wind speeds of 20 to 39 mph to create wind chill values of -40 to -43 for 7 hours from the late night of the 15th through the early morning of the 16th.

Cold/Wind Chill in CENTRAL AND SOUTHERN VALLEY, MONTANA
From 15-JAN-20 18:50:00 to 16-JAN-20 05:15:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

At the BLM Vandalia N mesonet site (MTM34), temperatures of -10 to -16 combined with wind speeds of 18 to 46 mph to create wind chill values of -40 to -44 for 6 hours from the late night of the 15th to the early morning of the 16th.  In addition, at the Saint Marie MARCO site (07MT), temperatures of -12 to -22 combined with wind speeds of 6 to 32 mph to create wind chill values of -40 to -45 for more than 9 hours from the evening of the 15th to the early morning of the 16th.

Cold/Wind Chill in CENTRAL AND SE PHILLIPS, MONTANA
From 15-JAN-20 20:15:00 to 15-JAN-20 22:35:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: Mesonet

At the Malta AIRNOW mesonet site (A3570), temperatures of -19 to -28 combined with wind speeds of 10 to 18 mph to create wind chill values of -44 to -52 for 10 hours from the night of the 15th through the early morning of the 16th. In addition, at the Malta airport AWOS site (KM75), temperatures of -15 to -17 combined with wind speeds of 11 to 16 mph to create wind chill values of near -40 to -42 for about 2 and 1/2 hours on the night of the 15th.