Station by station
When does the ground freeze in Montana?
Each bar runs from the typical first freeze to the typical last thaw at that depth, the median over the station's complete winters on record, with the typical number of frozen days after it. Frost reaches the deeper probes later in the winter. A depth that froze in fewer than half of its winters has no typical dates. Stations: 13 typically freeze.
Conrad Ag Rc
SCANTypically freezes to 20 inches, not to 40.
2 in2 inches: typically frozen from Nov 26 to Mar 15, a median of 85 frozen days.85 days
4 in4 inches: typically frozen from Dec 1 to Mar 2, a median of 74 frozen days.74 days
8 in8 inches: typically frozen from Jan 2 to Mar 3, a median of 31 frozen days.31 days
20 in20 inches: typically frozen from Jan 9 to Mar 29, a median of 74 frozen days.74 days
40 inFroze in 0 of 5 winters, no typical dates
Nov 3, 2026: Not frozen
Dillon 18 WSW
USCRNTypically freezes at every depth measured, down to 4 inches.
2 in2 inches: typically frozen from Nov 6 to Mar 17, a median of 128 frozen days.128 days
4 in4 inches: typically frozen from Nov 13 to Mar 24, a median of 124 frozen days.124 days
Nov 3, 2026: Not frozen
Fort Assiniboine #1
SCANTypically freezes to 8 inches, not to 20.
2 in2 inches: typically frozen from Dec 6 to Mar 3, a median of 57 frozen days.57 days
4 in4 inches: typically frozen from Dec 20 to Mar 8, a median of 72 frozen days.72 days
8 in8 inches: typically frozen from Dec 30 to Feb 20, a median of 34 frozen days.34 days
20 inFroze in 2 of 4 winters, no typical dates
40 inFroze in 0 of 4 winters, no typical dates
Nov 3, 2026: Not frozen
Jordan
SCANTypically freezes to 20 inches, not to 40.
2 in2 inches: typically frozen from Nov 19 to Mar 17, a median of 108 frozen days.108 days
4 in4 inches: typically frozen from Nov 29 to Mar 10, a median of 82 frozen days.82 days
8 in8 inches: typically frozen from Dec 15 to Mar 16, a median of 91 frozen days.91 days
20 in20 inches: typically frozen from Jan 5 to Mar 6, a median of 42 frozen days.42 days
40 inFroze in 2 of 5 winters, no typical dates
Nov 3, 2026: Not frozen
Lewistown 42 WSW
USCRNTypically freezes at every depth measured, down to 40 inches.
2 in2 inches: typically frozen from Nov 25 to Mar 12, a median of 86 frozen days.86 days
4 in4 inches: typically frozen from Nov 30 to Mar 12, a median of 69 frozen days.69 days
8 in8 inches: typically frozen from Jan 2 to Mar 6, a median of 44 frozen days.44 days
20 in20 inches: typically frozen from Jan 9 to Mar 2, a median of 22 frozen days.22 days
40 in40 inches: typically frozen from Jan 25 to Feb 9, a median of 10 frozen days.10 days
Nov 3, 2026: Not frozen
Lindsay
SCANTypically freezes to 20 inches, not to 40.
2 in2 inches: typically frozen from Nov 23 to Mar 8, a median of 94 frozen days.94 days
4 in4 inches: typically frozen from Nov 24 to Mar 17, a median of 102 frozen days.102 days
8 in8 inches: typically frozen from Jan 5 to Mar 14, a median of 80 frozen days.80 days
20 in20 inches: typically frozen from Jan 18 to Feb 16, a median of 29 frozen days.29 days
40 inFroze in 1 of 3 winters, no typical dates
Nov 3, 2026: Not frozen
Moccasin
SCANTypically freezes to 8 inches, not to 20.
2 in2 inches: typically frozen from Nov 27 to Mar 10, a median of 64 frozen days.64 days
4 in4 inches: typically frozen from Dec 20 to Feb 25, a median of 38 frozen days.38 days
8 in8 inches: typically frozen from Jan 17 to Feb 26, a median of 20 frozen days.20 days
20 inFroze in 0 of 5 winters, no typical dates
40 inFroze in 0 of 5 winters, no typical dates
Nov 3, 2026: Not frozen
Sidney
SCANTypically freezes to 20 inches, not to 40.
2 in2 inches: typically frozen from Nov 30 to Mar 11, a median of 88 frozen days.88 days
4 in4 inches: typically frozen from Dec 17 to Mar 20, a median of 93 frozen days.93 days
8 in8 inches: typically frozen from Dec 25 to Mar 23, a median of 88 frozen days.88 days
20 in20 inches: typically frozen from Jan 3 to Mar 11, a median of 63 frozen days.63 days
40 inFroze in 2 of 5 winters, no typical dates
Nov 3, 2026: Not frozen
St. Mary 1 SSW
USCRNTypically freezes at every depth measured, down to 4 inches.
2 in2 inches: typically frozen from Dec 17 to Mar 23, a median of 78 frozen days.78 days
4 in4 inches: typically frozen from Jan 6 to Mar 23, a median of 69 frozen days.69 days
No current reading
Table Mountain
SCANTypically freezes to 8 inches, not to 20.
2 in2 inches: typically frozen from Dec 9 to Mar 8, a median of 56 frozen days.56 days
4 in4 inches: typically frozen from Dec 17 to Feb 25, a median of 46 frozen days.46 days
8 in8 inches: typically frozen from Dec 29 to Feb 28, a median of 53 frozen days.53 days
20 inFroze in 1 of 5 winters, no typical dates
40 inFroze in 0 of 5 winters, no typical dates
Nov 3, 2026: Not frozen
Violett
SCANTypically freezes at every depth measured, down to 40 inches.
2 in2 inches: typically frozen from Nov 19 to Mar 10, a median of 99 frozen days.99 days
4 in4 inches: typically frozen from Nov 27 to Mar 13, a median of 88 frozen days.88 days
8 in8 inches: typically frozen from Nov 29 to Mar 15, a median of 96 frozen days.96 days
20 in20 inches: typically frozen from Dec 20 to Mar 3, a median of 46 frozen days.46 days
40 in40 inches: typically frozen from Jan 16 to Feb 2, a median of 12 frozen days.12 days
Nov 3, 2026: Not frozen
Wolf Point 29 ENE
USCRNTypically freezes at every depth measured, down to 40 inches.
2 in2 inches: typically frozen from Nov 24 to Mar 25, a median of 115 frozen days.115 days
4 in4 inches: typically frozen from Nov 25 to Mar 26, a median of 118 frozen days.118 days
8 in8 inches: typically frozen from Dec 1 to Mar 27, a median of 113 frozen days.113 days
20 in20 inches: typically frozen from Dec 8 to Mar 28, a median of 106 frozen days.106 days
40 in40 inches: typically frozen from Dec 17 to Mar 28, a median of 100 frozen days.100 days
Nov 3, 2026: Not frozen
Wolf Point 34 NE
USCRNTypically freezes at every depth measured, down to 40 inches.
2 in2 inches: typically frozen from Nov 21 to Apr 6, a median of 115 frozen days.115 days
4 in4 inches: typically frozen from Nov 24 to Mar 27, a median of 112 frozen days.112 days
8 in8 inches: typically frozen from Nov 28 to Mar 29, a median of 112 frozen days.112 days
20 in20 inches: typically frozen from Nov 29 to Mar 28, a median of 108 frozen days.108 days
40 in40 inches: typically frozen from Dec 8 to Mar 30, a median of 101 frozen days.101 days
Nov 3, 2026: Not frozen
A winter runs July to June. Our station readings come from one grass-covered site per station at five fixed depths, and often show shallower frost than regional figures.
