An area of freezing fog and low clouds moved south from Saskatchewan into northeastern Montana and remained over the area for a couple days.

Dense Fog in WIBAUX, MONTANA
From 11-JAN-23 03:55:00 to 12-JAN-23 06:35:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

At the Beach, ND airport ASOS site (K20U), visibility of a quarter mile or less was recorded for about 26 1/2 hours from early morning on the 11th to the morning of the 12th.

Dense Fog in MCCONE, MONTANA
From 11-JAN-23 05:10:00 to 12-JAN-23 04:55:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Multiple episodes of intermittent dense fog with visibility of a quarter mile or less occurred at the Circle Town County Airport AWOS (K4U6). The first episode lasted for 3 hours on the morning of the 11th. The second episode lasted 12 1/4 hours from the late afternoon of the 11th to the early morning on the 12th.

Dense Fog in CENTRAL AND SE PHILLIPS, MONTANA
From 10-JAN-23 20:55:00 to 12-JAN-23 05:15:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Multiple episodes of intermittent dense fog with visibility of a quarter mile or less occurred at the Malta Airport AWOS (KM75). The first episode lasted for 7 hours from the night of the 10th to the early morning of the 11th. The second episode lasted 2 1/2 hours on the morning of the 11th.  The third episode lasted 11 hours from the early nighttime hours of the 11th to the morning of the 12th.

Dense Fog in CENTRAL AND SOUTHERN VALLEY, MONTANA
From 10-JAN-23 20:35:00 to 12-JAN-23 13:20:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Multiple episodes of intermittent dense fog with visibility of a quarter mile or less occurred at the Glasgow Airport ASOS (KGGW). The first episode lasted for 20 1/2 hours from the night of the 10th to the afternoon of the 11th. The second episode lasted 18 hours from the night of the 11th to the early afternoon on the 12th.

Dense Fog in WESTERN ROOSEVELT, MONTANA
From 12-JAN-23 03:30:00 to 12-JAN-23 10:40:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Multiple episodes of intermittent dense fog with visibility of a quarter mile or less occurred at the Wolf Point Airport ASOS (KOLF). The first episode lasted for 2 1/4 hours on the early morning of the 12th. The second episode lasted 2 3/4 hours on the morning of the 12th.

Dense Fog in DAWSON, MONTANA
From 11-JAN-23 07:00:00 to 11-JAN-23 10:20:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

Multiple episodes of intermittent dense fog with visibility of a quarter mile or less occurred at the Glendive Airport ASOS (KGDV). The first episode lasted for 3 1/2 hours on the morning of the 11th. The second episode lasted 7 3/4 hours from the early morning to the mid morning on the 12th.

Dense Fog in SHERIDAN, MONTANA
From 11-JAN-23 01:55:00 to 13-JAN-23 00:55:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Multiple episodes of intermittent dense fog with visibility of a quarter mile or less occurred at the Sher-Wood Airport AWOS (KPWD). The first episode lasted for 5 hours on the morning of the 11th. The second episode lasted 27 1/2 hours from the night of the 11th to the early morning on the 13th.

Dense Fog in RICHLAND, MONTANA
From 11-JAN-23 07:56:00 to 11-JAN-23 11:15:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: ASOS

At the Sidney Airport ASOS site (KSDY), visibility of a quarter mile or less was recorded for about 3 1/4 hours on the morning of the 11th.