Frost dates in Montana
Across 216 NOAA stations in Montana, the average last spring frost ranges from April 30 at Norris Madison Pwr House to June 18 at Tizer Gardens.
| Adel | June 4 | September 12 | 98 |
| Alberton | May 18 | September 25 | 126 |
| Albion 1 N | June 2 | September 6 | 95 |
| Alder 17 S | June 6 | September 14 | 98 |
| Anaconda | June 1 | September 14 | 105 |
| Augusta | May 19 | September 21 | 125 |
| Austin 1 W | June 4 | September 14 | 100 |
| Baker | May 12 | September 26 | 135 |
| Baker Muni Airport | May 16 | September 26 | 132 |
| Biddle 8 Sw | May 14 | September 28 | 134 |
| Big Sandy | May 17 | September 25 | 128 |
| Big Timber | May 14 | September 26 | 133 |
| Bigfork 13 S | May 1 | October 15 | 165 |
| Billings Logan Intl Airport | May 4 | October 7 | 156 |
| Billings Wfo | May 5 | October 3 | 149 |
| Billings Wtp | May 10 | October 1 | 142 |
| Blackleaf | June 9 | September 3 | 86 |
| Boulder | June 7 | September 8 | 90 |
| Bozeman 6 W Exp Farm | May 23 | September 23 | 123 |
| Bozeman Gallatin Fld | May 26 | September 16 | 112 |
| Bozeman Montana State Univ | May 26 | September 22 | 116 |
| Brady 27 Ene (The Knees) | May 13 | September 29 | 137 |
| Brandenberg | May 18 | September 22 | 126 |
| Bredette | May 20 | September 21 | 122 |
| Bridger 2 N | May 14 | September 24 | 129 |
| Broadus | May 16 | September 28 | 135 |
| Brockway 3 Wsw | May 20 | September 19 | 121 |
| Busby | May 23 | September 15 | 113 |
| Butte Bert Mooney Airport | June 13 | September 5 | 83 |
| Bynum 4 Sse | May 16 | September 27 | 133 |
| Carlyle 13 Nw | May 18 | September 29 | 134 |
| Carter 14 W | May 23 | September 23 | 120 |
| Cascade 5 S | May 21 | September 19 | 120 |
| Chester | May 24 | September 17 | 115 |
| Chinook | May 14 | September 23 | 130 |
| Chinook 35Se | May 23 | September 23 | 121 |
| Choteau | May 28 | September 12 | 104 |
| Choteau 8Ne | May 20 | September 22 | 123 |
| Circle | May 17 | September 22 | 126 |
| Cohagen | May 25 | September 14 | 110 |
| Colstrip | May 15 | September 30 | 138 |
| Columbus | May 27 | September 14 | 108 |
| Conrad | May 20 | September 19 | 119 |
| Content 4 Nne | May 25 | September 14 | 110 |
| Creston | May 12 | September 25 | 134 |
| Culbertson | May 21 | September 20 | 120 |
| Cut Bank Muni Airport | May 24 | September 15 | 113 |
| Darby | May 24 | September 23 | 118 |
| Del Bonita | May 28 | September 16 | 110 |
| Denton | June 1 | September 11 | 101 |
| Dillon Airport | June 2 | September 13 | 101 |
| Dillon U Of Montana Western | June 5 | September 13 | 98 |
| Divide | June 10 | September 7 | 85 |
| Dunkirk 19Nne | May 23 | September 14 | 112 |
| E Glacier | June 8 | September 5 | 88 |
| Ekalaka | May 20 | September 23 | 126 |
| Elliston | June 9 | September 8 | 91 |
| Ennis | June 16 | September 4 | 78 |
| Eureka Rs | May 11 | September 27 | 138 |
| Fairfield | May 13 | September 27 | 135 |
| Flatwillow 4 Ene | May 16 | September 28 | 132 |
| Forsyth | May 9 | September 29 | 142 |
| Fortine 1 N | May 16 | September 18 | 121 |
| Ft Assiniboine | May 15 | September 24 | 130 |
| Ft Belknap 2 Sw | May 16 | September 22 | 128 |
| Ft Benton | May 15 | September 22 | 129 |
| Ft Peck Pwr Plt | May 8 | October 1 | 145 |
| Gardiner | May 21 | September 27 | 128 |
| Geraldine | May 14 | September 26 | 134 |
| Gibson 2 Ne | May 27 | September 18 | 113 |
| Gibson Dam | June 12 | September 8 | 88 |
| Gildford | May 24 | September 15 | 114 |
| Glasgow #2 | May 3 | October 1 | 151 |
| Glasgow Intl Airport | May 6 | September 30 | 145 |
| Glendive | May 3 | October 4 | 153 |
| Grass Range | May 20 | September 24 | 126 |
| Great Falls 16St | May 6 | October 1 | 147 |
| Great Falls Intl Airport | May 19 | September 24 | 126 |
| Great Falls Wfo | May 12 | September 28 | 138 |
| Hamilton | May 21 | September 22 | 122 |
| Hardin | May 13 | September 29 | 135 |
| Harlem | May 16 | September 21 | 125 |
| Harlem 20S | May 24 | September 22 | 118 |
| Harlowton | May 23 | September 16 | 113 |
| Harlowton 11Nw | May 30 | September 20 | 110 |
| Havre City Co Airport | May 15 | September 23 | 129 |
| Hebgen Dam | June 15 | September 10 | 87 |
| Helena Rgnl Airport | May 9 | September 30 | 142 |
| Heron 2 Nw | May 20 | September 20 | 119 |
| Highwood 7 Ne | May 7 | October 2 | 149 |
| Hinsdale 4 Sw | May 15 | September 26 | 132 |
| Holter Dam | May 19 | September 24 | 124 |
| Hungry Horse Dam | May 9 | October 1 | 141 |
| Huntley Exp Stn | May 12 | September 25 | 136 |
| Hysham | May 10 | September 29 | 141 |
| Hysham 25 Sse | May 26 | September 16 | 111 |
| Ingomar 9 E | May 21 | September 19 | 120 |
| Joliet | May 29 | September 15 | 107 |
| Joplin | May 21 | September 19 | 119 |
| Jordan | May 21 | September 18 | 118 |
| Jordan Airport | May 18 | September 20 | 123 |
| Judith Gap | June 1 | September 15 | 104 |
| Judith Gap 13 E | June 3 | September 15 | 100 |
| Kalispell Glacier Airport | May 31 | September 10 | 100 |
| Laurin 2Ne | May 24 | September 22 | 117 |
| Lewistown | May 14 | September 28 | 135 |
| Lewistown 11 Sse | May 31 | September 14 | 105 |
| Lewistown 11Ese | May 19 | September 25 | 128 |
| Lewistown 42 Wsw | June 15 | September 4 | 77 |
| Lewistown Muni Airport | May 23 | September 21 | 119 |
| Libby | May 10 | September 26 | 137 |
| Libby 1 Ne Rs | May 23 | September 21 | 120 |
| Libby Dam (Base) | May 11 | October 1 | 142 |
| Lima | June 11 | September 10 | 89 |
| Lindbergh Lake | May 20 | September 22 | 120 |
| Livingston 12 S | May 19 | September 25 | 125 |
| Livingston Mission Fld | May 27 | September 14 | 108 |
| Logan Landfill | May 26 | September 15 | 111 |
| Loma | May 20 | September 19 | 120 |
| Malta | May 10 | September 29 | 139 |
| Malta 35 S | May 16 | September 23 | 128 |
| Malta 7 E | May 7 | September 28 | 143 |
| Martinsdale 3 Nnw | June 3 | September 8 | 94 |
| Medicine Lake 3 Se | May 16 | September 18 | 125 |
| Melstone | May 10 | September 29 | 141 |
| Melville 4 W | June 9 | September 7 | 88 |
| Mildred 5 N | May 20 | September 22 | 124 |
| Miles City F Wiley Fld | May 8 | September 30 | 144 |
| Millegan 14 Se | June 11 | September 6 | 86 |
| Missoula 2 Ne | May 10 | October 1 | 143 |
| Missoula 6 Nw Wfo | May 6 | October 4 | 151 |
| Missoula Intl Airport | May 16 | September 26 | 130 |
| Mizpah 4 Nnw | May 22 | September 15 | 117 |
| Moccasin Exp Stn | May 28 | September 20 | 112 |
| Moorhead 9 Ne | May 17 | September 22 | 126 |
| Mosby 4 Ene | May 5 | October 4 | 151 |
| Mystic Lake | June 5 | September 14 | 99 |
| Nashua #2 | May 12 | September 24 | 134 |
| Neihart 8 Nnw | June 6 | September 12 | 99 |
| Norris Madison Pwr House | April 30 | October 10 | 162 |
| Nye #2 | June 1 | September 11 | 100 |
| Opheim 10 N | June 1 | September 7 | 99 |
| Opheim 12 Sse | June 5 | September 2 | 89 |
| Plentywood | May 25 | September 14 | 111 |
| Plevna | May 21 | September 20 | 121 |
| Polson | May 10 | October 5 | 147 |
| Pompeys Pillar 15N | May 22 | September 22 | 121 |
| Port Of Morgan | May 19 | September 22 | 124 |
| Powderville 8 Nne | May 13 | September 25 | 132 |
| Rapelje | May 24 | September 21 | 116 |
| Raymond Border Stn | May 19 | September 23 | 125 |
| Raynesford 2 Nnw | May 22 | September 23 | 123 |
| Red Lodge | June 3 | September 19 | 106 |
| Redstone | May 28 | September 7 | 101 |
| Ridgeway 1 S | May 17 | September 22 | 127 |
| Rock Springs | May 15 | September 25 | 132 |
| Rogers Pass 9 Nne | May 21 | September 15 | 115 |
| Roundup | May 20 | September 21 | 124 |
| Roundup 15 Sw | May 22 | September 15 | 114 |
| Roy 8 Ne | May 14 | September 24 | 134 |
| Rudyard 19S | May 23 | September 19 | 119 |
| Rudyard 21 N | May 30 | September 11 | 103 |
| Ryegate | May 17 | September 23 | 127 |
| Ryegate 18 Nnw | May 26 | September 18 | 112 |
| Saco 1 Nnw | May 15 | September 23 | 130 |
| Saint Ignatius | May 12 | October 2 | 142 |
| Sand Creek | May 12 | September 27 | 136 |
| Savage | May 12 | September 25 | 135 |
| Scobey 4 Nw | May 28 | September 6 | 99 |
| Shelby | May 23 | September 16 | 115 |
| Shonkin 7 S | May 24 | September 21 | 119 |
| Sidney | May 11 | September 27 | 137 |
| Simpson 6 N - Wildhorse | May 26 | September 15 | 110 |
| Skq Dam | May 15 | September 28 | 134 |
| Sonnette 7 Sw | May 25 | September 19 | 115 |
| St Marie | May 13 | September 27 | 134 |
| St Mary | June 12 | September 5 | 82 |
| St. Mary 1 Ssw | June 3 | September 8 | 94 |
| Stanford | May 25 | September 21 | 118 |
| Stevensville | May 22 | September 19 | 115 |
| Sun Rvr 4 S | June 2 | September 10 | 96 |
| Sunburst 8 E | May 17 | September 25 | 129 |
| Superior | May 17 | September 23 | 125 |
| Swan Lake | May 17 | September 19 | 121 |
| Sweetgrass | May 15 | September 25 | 132 |
| Terry | May 12 | September 28 | 137 |
| Terry 21 Nnw | May 26 | September 17 | 113 |
| Thompson Falls Ph | May 7 | October 4 | 150 |
| Tiber Dam | May 16 | September 23 | 129 |
| Tizer Gardens | June 18 | September 5 | 81 |
| Townsend 3Se | May 19 | September 19 | 122 |
| Trident | May 9 | September 27 | 139 |
| Trout Creek Rs | May 20 | September 21 | 122 |
| Troy | May 14 | September 25 | 132 |
| Turner 11N | May 19 | September 21 | 124 |
| Twin Bridges | June 8 | September 2 | 82 |
| Valentine | May 18 | September 21 | 124 |
| Valier | May 17 | September 24 | 129 |
| Vida 6 Ne | May 16 | September 22 | 129 |
| Virginia City | June 4 | September 18 | 106 |
| W Glacier | May 18 | September 20 | 124 |
| Westby | May 18 | September 21 | 125 |
| Western Ag Rsch Ctr | May 23 | September 21 | 118 |
| White Sulphur Springs #2 | June 4 | September 11 | 97 |
| Whitefish | May 16 | September 25 | 129 |
| Wibaux 2 E | May 27 | September 16 | 112 |
| Wilsall 1S | June 4 | September 6 | 92 |
| Wilsall 8 Ene | June 8 | September 7 | 89 |
| Winifred | May 16 | September 23 | 127 |
| Wolf Point 29 Ene | May 24 | September 14 | 110 |
| Wolf Point 34 Ne | May 13 | September 28 | 137 |
| Wolf Point Intl Airport | May 16 | September 20 | 125 |
| Wolf Pt | May 8 | September 28 | 143 |
| Wyola 1 Sw | May 21 | September 17 | 117 |
| Yellowtail Dam | May 7 | October 5 | 151 |
| Zortman | May 18 | September 23 | 126 |
Sources
- U.S. Annual/Seasonal Climate Normals, 1991 to 2020 (freeze probability dates by station), NOAA National Centers for Environmental Information, checked 1 November 2026
- Annual/Seasonal Normals 1991 to 2020 documentation, NOAA National Centers for Environmental Information, checked 1 November 2026
- 2024 Gazetteer Files, ZIP Code Tabulation Areas, US Census Bureau, checked 1 November 2026