Areas of dense freezing fog formed over northeast Montana, with the river valleys of the Milk, Missouri and Yellowstone Rivers being most prone for development.

Dense Fog in WIBAUX, MONTANA
From 03-JAN-23 04:55:00 to 03-JAN-23 08:55:00 (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 4 hours from early to mid morning on the 3rd.

Dense Fog in MCCONE, MONTANA
From 04-JAN-23 03:25:00 to 04-JAN-23 07:40:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

At the Circle Town County airport AWOS site (K4U6), visibility of a quarter mile or less was recorded for about 4 1/4 hours during the early morning of the 4th.

Dense Fog in RICHLAND, MONTANA
From 03-JAN-23 04:11:00 to 04-JAN-23 03:50:00 (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 Sidney Airport ASOS (KSDY). The first episode lasted for 18 3/4 hours from the early morning to the late night on the 3rd. The second episode lasted 2 3/4 hours on the early morning of the 4th.

Dense Fog in CENTRAL AND SOUTHERN VALLEY, MONTANA
From 02-JAN-23 06:40:00 to 04-JAN-23 11:10:00 (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 4 1/2 hours from the early morning to the late morning on the 2nd. The second episode lasted 16 hours from the early morning to the early nighttime hours on the 3rd. The third episode lasted 10 1/4 hours from the early morning to the late morning of the 4th.

Dense Fog in EASTERN ROOSEVELT, MONTANA
From 02-JAN-23 02:10:00 to 04-JAN-23 22:40:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

Multiple episodes of dense fog with visibility of a quarter mile or less occurred at the Big Sky Field Airport AWOS (KS85).  The first episode lasted for 7 3/4 hours from the early morning to late morning on the 2nd.  The second episode lasted 8 3/4 hours from the early morning to the late morning of the 3rd.  The third episode lasted 21 hours from the late afternoon of the 3rd to the early afternoon on the 4th.  The last episode lasted 4 1/2 hours from the early evening to the late night on the 4th.

Dense Fog in WESTERN ROOSEVELT, MONTANA
From 03-JAN-23 04:25:00 to 04-JAN-23 09:25:00 (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 10 1/4 hours from the early morning to the mid afternoon on the 3rd. The second episode lasted 3 1/2 hours from the evening to the early nighttime hours on the 3rd. The third episode lasted 1 1/2 hours on the morning of the 4th.

Dense Fog in CENTRAL AND SE PHILLIPS, MONTANA
From 01-JAN-23 23:35:00 to 04-JAN-23 05:35:00 (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 late night of the 1st to the morning of the 2nd. The second episode lasted 8 hours from the night of the 3rd to the early morning on the 4th.

Dense Fog in DAWSON, MONTANA
From 03-JAN-23 12:22:00 to 04-JAN-23 09:14:00 (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 2 1/4 hours in the early morning on the 3rd. The second episode lasted 4 hours from the early morning to the mid morning of the 3rd. The third episode lasted 5 1/2 hours from the late morning to the late afternoon on the 3rd. The fourth episode lasted 4 1/2 hours on the early morning of the 4th.  The last episode lasted 1 1/4 hours on the  mid morning of the 4th.

Dense Fog in SHERIDAN, MONTANA
From 03-JAN-23 17:10:00 to 04-JAN-23 13:35:00 (MST-7)
Property damage: 0.00K
Crop damage: 0.00K
Reported by: AWOS

At the Sher-Wood airport AWOS site (KPWD), visibility of a quarter mile or less was recorded for about 20 1/2 hours from late afternoon on the 3rd to early afternoon on the 4th.