Frost Dates in Montana
Across 216 NOAA weather stations in Montana, the average last spring frost falls between April 30 at Norris Madison Pwr House and June 18 at Tizer Gardens. At a typical Montana station it is around May 20, with the first fall frost around September 22 and a frost-free season of about 123 days.
Find the frost dates for your ZIP code
A typical Montana season
What shapes frost dates in Montana
- The frost-free season ranges from 77 days at Lewistown 42 WSW to 165 days at Bigfork 13 S.
- Elevation matters: Mystic Lake, at 6,544 ft, averages its last frost on June 5, while Troy, at 1,929 ft, averages May 14.
- Gardens in valleys and low spots, where cold air settles, often frost a week or more later in spring than the nearest station.
Frost dates at major airports
| Station | Last frost | Safer date | First frost | Season (days) |
|---|---|---|---|---|
| Baker Muni Airport | May 16 | May 29 | Sep 26 | 132 |
| Billings Logan Intl Airport | May 4 | May 18 | Oct 7 | 156 |
| Bozeman Gallatin Fld | May 26 | Jun 12 | Sep 16 | 112 |
| Butte Bert Mooney Airport | Jun 13 | Jul 1 | Sep 5 | 83 |
| Cut Bank Muni Airport | May 24 | Jun 5 | Sep 15 | 113 |
| Dillon Airport | Jun 2 | Jun 21 | Sep 13 | 101 |
| Glasgow Intl Airport | May 6 | May 18 | Sep 30 | 145 |
| Great Falls Intl Airport | May 19 | Jun 2 | Sep 24 | 126 |
| Havre City Co Airport | May 15 | May 27 | Sep 23 | 129 |
| Helena Rgnl Airport | May 9 | May 25 | Sep 30 | 142 |
| Jordan Airport | May 18 | May 31 | Sep 20 | 123 |
| Lewistown 42 WSW | Jun 15 | Jul 8 | Sep 4 | 77 |
| Lewistown Muni Airport | May 23 | Jun 8 | Sep 21 | 119 |
| Livingston Mission Fld | May 27 | Jun 14 | Sep 14 | 108 |
| Miles City F Wiley Fld | May 8 | May 21 | Sep 30 | 144 |
| Missoula Intl Airport | May 16 | Jun 1 | Sep 26 | 130 |
| St Marie | May 13 | May 26 | Sep 27 | 134 |
| St. Mary 1 SSW | Jun 3 | Jun 23 | Sep 8 | 94 |
| Superior | May 17 | Jun 8 | Sep 23 | 125 |
| Wolf Point 29 ENE | May 24 | Jun 6 | Sep 14 | 110 |
| Wolf Point 34 NE | May 13 | May 25 | Sep 28 | 137 |
| Wolf Point Intl Airport | May 16 | May 29 | Sep 20 | 125 |
All 216 weather stations in Montana
| Station | Elevation (ft) | Last frost | Safer date | First frost | Season (days) |
|---|---|---|---|---|---|
| Adel | 5,017 | Jun 4 | Jun 22 | Sep 12 | 98 |
| Alberton | 3,060 | May 18 | Jun 6 | Sep 25 | 126 |
| Albion 1 N | 3,312 | Jun 2 | Jun 21 | Sep 6 | 95 |
| Alder 17 S | 5,850 | Jun 6 | Jun 25 | Sep 14 | 98 |
| Anaconda | 5,230 | Jun 1 | Jun 25 | Sep 14 | 105 |
| Augusta | 4,070 | May 19 | May 31 | Sep 21 | 125 |
| Austin 1 W | 4,851 | Jun 4 | Jun 18 | Sep 14 | 100 |
| Baker | 2,933 | May 12 | May 27 | Sep 26 | 135 |
| Baker Muni Airport | 2,971 | May 16 | May 29 | Sep 26 | 132 |
| Biddle 8 SW | 3,631 | May 14 | May 27 | Sep 28 | 134 |
| Big Sandy | 2,770 | May 17 | Jun 4 | Sep 25 | 128 |
| Big Timber | 4,100 | May 14 | May 27 | Sep 26 | 133 |
| Bigfork 13 S | 2,979 | May 1 | May 16 | Oct 15 | 165 |
| Billings Logan Intl Airport | 3,581 | May 4 | May 18 | Oct 7 | 156 |
| Billings Wfo | 3,185 | May 5 | May 21 | Oct 3 | 149 |
| Billings Wtp | 3,097 | May 10 | May 24 | Oct 1 | 142 |
| Blackleaf | 4,235 | Jun 9 | Jul 2 | Sep 3 | 86 |
| Boulder | 4,904 | Jun 7 | Jun 25 | Sep 8 | 90 |
| Bozeman 6 W Exp Farm | 4,775 | May 23 | Jun 12 | Sep 23 | 123 |
| Bozeman Gallatin Fld | 4,427 | May 26 | Jun 12 | Sep 16 | 112 |
| Bozeman Montana State Univ | 4,913 | May 26 | Jun 14 | Sep 22 | 116 |
| Brady 27 ENE (the Knees) | 3,325 | May 13 | May 29 | Sep 29 | 137 |
| Brandenberg | 2,770 | May 18 | May 30 | Sep 22 | 126 |
| Bredette | 2,313 | May 20 | Jun 1 | Sep 21 | 122 |
| Bridger 2 N | 3,583 | May 14 | May 30 | Sep 24 | 129 |
| Broadus | 3,032 | May 16 | May 29 | Sep 28 | 135 |
| Brockway 3 WSW | 2,630 | May 20 | Jun 5 | Sep 19 | 121 |
| Busby | 3,430 | May 23 | Jun 7 | Sep 15 | 113 |
| Butte Bert Mooney Airport | 5,506 | Jun 13 | Jul 1 | Sep 5 | 83 |
| Bynum 4 SSE | 4,039 | May 16 | May 28 | Sep 27 | 133 |
| Carlyle 13 NW | 3,145 | May 18 | May 31 | Sep 29 | 134 |
| Carter 14 W | 3,450 | May 23 | Jun 9 | Sep 23 | 120 |
| Cascade 5 S | 3,360 | May 21 | Jun 6 | Sep 19 | 120 |
| Chester | 3,132 | May 24 | Jun 9 | Sep 17 | 115 |
| Chinook | 2,420 | May 14 | May 27 | Sep 23 | 130 |
| Chinook 35SE | 3,360 | May 23 | Jun 3 | Sep 23 | 121 |
| Choteau | 3,845 | May 28 | Jun 20 | Sep 12 | 104 |
| Choteau 8NE | 3,741 | May 20 | Jun 4 | Sep 22 | 123 |
| Circle | 2,480 | May 17 | May 31 | Sep 22 | 126 |
| Cohagen | 2,720 | May 25 | Jun 9 | Sep 14 | 110 |
| Colstrip | 3,218 | May 15 | May 28 | Sep 30 | 138 |
| Columbus | 3,602 | May 27 | Jun 12 | Sep 14 | 108 |
| Conrad | 3,550 | May 20 | Jun 3 | Sep 19 | 119 |
| Content 4 NNE | 2,325 | May 25 | Jun 8 | Sep 14 | 110 |
| Creston | 2,935 | May 12 | May 26 | Sep 25 | 134 |
| Culbertson | 1,940 | May 21 | Jun 3 | Sep 20 | 120 |
| Cut Bank Muni Airport | 3,838 | May 24 | Jun 5 | Sep 15 | 113 |
| Darby | 3,880 | May 24 | Jun 14 | Sep 23 | 118 |
| Del Bonita | 4,337 | May 28 | Jun 12 | Sep 16 | 110 |
| Denton | 3,610 | Jun 1 | Jun 26 | Sep 11 | 101 |
| Dillon Airport | 5,200 | Jun 2 | Jun 21 | Sep 13 | 101 |
| Dillon U Of Montana Western | 5,129 | Jun 5 | Jun 23 | Sep 13 | 98 |
| Divide | 5,350 | Jun 10 | Jul 2 | Sep 7 | 85 |
| Dunkirk 19NNE | 3,323 | May 23 | Jun 8 | Sep 14 | 112 |
| E Glacier | 4,806 | Jun 8 | Jul 1 | Sep 5 | 88 |
| Ekalaka | 3,432 | May 20 | Jun 1 | Sep 23 | 126 |
| Elliston | 5,080 | Jun 9 | Jun 26 | Sep 8 | 91 |
| Ennis | 4,953 | Jun 16 | Jul 6 | Sep 4 | 78 |
| Eureka Rs | 2,532 | May 11 | May 25 | Sep 27 | 138 |
| Fairfield | 3,983 | May 13 | Jun 1 | Sep 27 | 135 |
| Flatwillow 4 ENE | 3,292 | May 16 | May 31 | Sep 28 | 132 |
| Forsyth | 2,515 | May 9 | May 21 | Sep 29 | 142 |
| Fortine 1 N | 3,000 | May 16 | Jun 3 | Sep 18 | 121 |
| Ft Assiniboine | 2,675 | May 15 | May 28 | Sep 24 | 130 |
| Ft Belknap 2 SW | 2,527 | May 16 | May 28 | Sep 22 | 128 |
| Ft Benton | 2,649 | May 15 | May 30 | Sep 22 | 129 |
| Ft Peck Pwr Plt | 2,071 | May 8 | May 20 | Oct 1 | 145 |
| Gardiner | 5,275 | May 21 | Jun 9 | Sep 27 | 128 |
| Geraldine | 3,145 | May 14 | May 28 | Sep 26 | 134 |
| Gibson 2 NE | 4,444 | May 27 | Jun 12 | Sep 18 | 113 |
| Gibson Dam | 4,590 | Jun 12 | Jul 5 | Sep 8 | 88 |
| Gildford | 2,820 | May 24 | Jun 7 | Sep 15 | 114 |
| Glasgow #2 | 2,090 | May 3 | May 15 | Oct 1 | 151 |
| Glasgow Intl Airport | 2,285 | May 6 | May 18 | Sep 30 | 145 |
| Glendive | 2,075 | May 3 | May 16 | Oct 4 | 153 |
| Grass Range | 3,490 | May 20 | Jun 6 | Sep 24 | 126 |
| Great Falls 16ST | 3,505 | May 6 | May 19 | Oct 1 | 147 |
| Great Falls Intl Airport | 3,664 | May 19 | Jun 2 | Sep 24 | 126 |
| Great Falls Wfo | 3,705 | May 12 | May 27 | Sep 28 | 138 |
| Hamilton | 3,585 | May 21 | Jun 6 | Sep 22 | 122 |
| Hardin | 2,880 | May 13 | May 26 | Sep 29 | 135 |
| Harlem | 2,371 | May 16 | May 31 | Sep 21 | 125 |
| Harlem 20S | 2,695 | May 24 | Jun 11 | Sep 22 | 118 |
| Harlowton | 4,222 | May 23 | Jun 6 | Sep 16 | 113 |
| Harlowton 11NW | 4,954 | May 30 | Jun 17 | Sep 20 | 110 |
| Havre City Co Airport | 2,585 | May 15 | May 27 | Sep 23 | 129 |
| Hebgen Dam | 6,489 | Jun 15 | Jul 7 | Sep 10 | 87 |
| Helena Rgnl Airport | 3,828 | May 9 | May 25 | Sep 30 | 142 |
| Heron 2 NW | 2,240 | May 20 | Jun 5 | Sep 20 | 119 |
| Highwood 7 NE | 3,600 | May 7 | May 21 | Oct 2 | 149 |
| Hinsdale 4 SW | 2,805 | May 15 | May 30 | Sep 26 | 132 |
| Holter Dam | 3,487 | May 19 | Jun 8 | Sep 24 | 124 |
| Hungry Horse Dam | 3,160 | May 9 | May 30 | Oct 1 | 141 |
| Huntley Exp Stn | 3,034 | May 12 | May 26 | Sep 25 | 136 |
| Hysham | 2,669 | May 10 | May 22 | Sep 29 | 141 |
| Hysham 25 SSE | 3,100 | May 26 | Jun 13 | Sep 16 | 111 |
| Ingomar 9 E | 2,800 | May 21 | Jun 4 | Sep 19 | 120 |
| Joliet | 3,838 | May 29 | Jun 17 | Sep 15 | 107 |
| Joplin | 3,323 | May 21 | Jun 6 | Sep 19 | 119 |
| Jordan | 2,620 | May 21 | Jun 2 | Sep 18 | 118 |
| Jordan Airport | 2,662 | May 18 | May 31 | Sep 20 | 123 |
| Judith Gap | 4,630 | Jun 1 | Jun 16 | Sep 15 | 104 |
| Judith Gap 13 E | 4,791 | Jun 3 | Jun 25 | Sep 15 | 100 |
| Kalispell Glacier Airport | 2,957 | May 31 | Jun 22 | Sep 10 | 100 |
| Laurin 2NE | 5,198 | May 24 | Jun 13 | Sep 22 | 117 |
| Lewistown | 3,911 | May 14 | May 27 | Sep 28 | 135 |
| Lewistown 11 SSE | 4,965 | May 31 | Jun 18 | Sep 14 | 105 |
| Lewistown 11ESE | 5,028 | May 19 | Jun 1 | Sep 25 | 128 |
| Lewistown 42 WSW | 5,070 | Jun 15 | Jul 8 | Sep 4 | 77 |
| Lewistown Muni Airport | 4,145 | May 23 | Jun 8 | Sep 21 | 119 |
| Libby | 2,140 | May 10 | May 26 | Sep 26 | 137 |
| Libby 1 NE Rs | 2,096 | May 23 | Jun 7 | Sep 21 | 120 |
| Libby Dam (base) | 2,110 | May 11 | May 27 | Oct 1 | 142 |
| Lima | 6,279 | Jun 11 | Jun 30 | Sep 10 | 89 |
| Lindbergh Lake | 4,320 | May 20 | Jun 7 | Sep 22 | 120 |
| Livingston 12 S | 5,044 | May 19 | Jun 11 | Sep 25 | 125 |
| Livingston Mission Fld | 4,643 | May 27 | Jun 14 | Sep 14 | 108 |
| Logan Landfill | 4,243 | May 26 | Jun 12 | Sep 15 | 111 |
| Loma | 2,578 | May 20 | Jun 3 | Sep 19 | 120 |
| Malta | 2,262 | May 10 | May 22 | Sep 29 | 139 |
| Malta 35 S | 2,615 | May 16 | May 29 | Sep 23 | 128 |
| Malta 7 E | 2,231 | May 7 | May 21 | Sep 28 | 143 |
| Martinsdale 3 NNW | 4,800 | Jun 3 | Jun 25 | Sep 8 | 94 |
| Medicine Lake 3 SE | 1,942 | May 16 | May 30 | Sep 18 | 125 |
| Melstone | 2,932 | May 10 | May 23 | Sep 29 | 141 |
| Melville 4 W | 5,365 | Jun 9 | Jun 27 | Sep 7 | 88 |
| Mildred 5 N | 2,482 | May 20 | Jun 2 | Sep 22 | 124 |
| Miles City F Wiley Fld | 2,624 | May 8 | May 21 | Sep 30 | 144 |
| Millegan 14 SE | 4,970 | Jun 11 | Jul 3 | Sep 6 | 86 |
| Missoula 2 NE | 3,420 | May 10 | May 28 | Oct 1 | 143 |
| Missoula 6 NW Wfo | 3,197 | May 6 | May 19 | Oct 4 | 151 |
| Missoula Intl Airport | 3,192 | May 16 | Jun 1 | Sep 26 | 130 |
| Mizpah 4 NNW | 2,480 | May 22 | Jun 7 | Sep 15 | 117 |
| Moccasin Exp Stn | 4,300 | May 28 | Jun 19 | Sep 20 | 112 |
| Moorhead 9 NE | 3,220 | May 17 | May 31 | Sep 22 | 126 |
| Mosby 4 ENE | 2,910 | May 5 | May 26 | Oct 4 | 151 |
| Mystic Lake | 6,544 | Jun 5 | Jun 21 | Sep 14 | 99 |
| Nashua #2 | 2,067 | May 12 | May 26 | Sep 24 | 134 |
| Neihart 8 NNW | 5,230 | Jun 6 | Jun 28 | Sep 12 | 99 |
| Norris Madison Pwr House | 4,745 | Apr 30 | May 14 | Oct 10 | 162 |
| Nye #2 | 4,840 | Jun 1 | Jun 21 | Sep 11 | 100 |
| Opheim 10 N | 2,878 | Jun 1 | Jun 18 | Sep 7 | 99 |
| Opheim 12 SSE | 2,936 | Jun 5 | Jun 23 | Sep 2 | 89 |
| Plentywood | 2,048 | May 25 | Jun 8 | Sep 14 | 111 |
| Plevna | 2,780 | May 21 | Jun 4 | Sep 20 | 121 |
| Polson | 3,010 | May 10 | May 26 | Oct 5 | 147 |
| Pompeys Pillar 15N | 3,390 | May 22 | Jun 7 | Sep 22 | 121 |
| Port Of Morgan | 2,830 | May 19 | Jun 2 | Sep 22 | 124 |
| Powderville 8 NNE | 2,800 | May 13 | May 31 | Sep 25 | 132 |
| Rapelje | 4,068 | May 24 | Jun 11 | Sep 21 | 116 |
| Raymond Border Stn | 2,345 | May 19 | Jun 1 | Sep 23 | 125 |
| Raynesford 2 NNW | 4,215 | May 22 | Jun 9 | Sep 23 | 123 |
| Red Lodge | 5,646 | Jun 3 | Jun 18 | Sep 19 | 106 |
| Redstone | 2,106 | May 28 | Jun 13 | Sep 7 | 101 |
| Ridgeway 1 S | 3,316 | May 17 | Jun 1 | Sep 22 | 127 |
| Rock Springs | 3,024 | May 15 | May 27 | Sep 25 | 132 |
| Rogers Pass 9 NNE | 4,200 | May 21 | Jun 8 | Sep 15 | 115 |
| Roundup | 3,200 | May 20 | Jun 2 | Sep 21 | 124 |
| Roundup 15 SW | 3,386 | May 22 | Jun 4 | Sep 15 | 114 |
| Roy 8 NE | 3,085 | May 14 | May 29 | Sep 24 | 134 |
| Rudyard 19S | 2,878 | May 23 | Jun 3 | Sep 19 | 119 |
| Rudyard 21 N | 3,000 | May 30 | Jun 15 | Sep 11 | 103 |
| Ryegate | 3,650 | May 17 | May 30 | Sep 23 | 127 |
| Ryegate 18 NNW | 4,440 | May 26 | Jun 13 | Sep 18 | 112 |
| Saco 1 NNW | 2,185 | May 15 | May 26 | Sep 23 | 130 |
| Saint Ignatius | 2,915 | May 12 | Jun 1 | Oct 2 | 142 |
| Sand Creek | 2,910 | May 12 | May 27 | Sep 27 | 136 |
| Savage | 1,978 | May 12 | May 26 | Sep 25 | 135 |
| Scobey 4 NW | 2,390 | May 28 | Jun 13 | Sep 6 | 99 |
| Shelby | 3,325 | May 23 | Jun 6 | Sep 16 | 115 |
| Shonkin 7 S | 4,300 | May 24 | Jun 10 | Sep 21 | 119 |
| Sidney | 1,933 | May 11 | May 25 | Sep 27 | 137 |
| Simpson 6 N - Wildhorse | 2,815 | May 26 | Jun 8 | Sep 15 | 110 |
| Skq Dam | 2,730 | May 15 | Jun 1 | Sep 28 | 134 |
| Sonnette 7 SW | 3,914 | May 25 | Jun 7 | Sep 19 | 115 |
| St Marie | 2,756 | May 13 | May 26 | Sep 27 | 134 |
| St Mary | 4,560 | Jun 12 | Jul 3 | Sep 5 | 82 |
| St. Mary 1 SSW | 4,555 | Jun 3 | Jun 23 | Sep 8 | 94 |
| Stanford | 4,860 | May 25 | Jun 15 | Sep 21 | 118 |
| Stevensville | 3,375 | May 22 | Jun 13 | Sep 19 | 115 |
| Sun Rvr 4 S | 3,600 | Jun 2 | Jun 21 | Sep 10 | 96 |
| Sunburst 8 E | 3,700 | May 17 | May 31 | Sep 25 | 129 |
| Superior | 2,710 | May 17 | Jun 8 | Sep 23 | 125 |
| Swan Lake | 3,100 | May 17 | Jun 4 | Sep 19 | 121 |
| Sweetgrass | 3,510 | May 15 | May 28 | Sep 25 | 132 |
| Terry | 2,250 | May 12 | May 25 | Sep 28 | 137 |
| Terry 21 NNW | 3,142 | May 26 | Jun 13 | Sep 17 | 113 |
| Thompson Falls Ph | 2,380 | May 7 | May 19 | Oct 4 | 150 |
| Tiber Dam | 2,850 | May 16 | May 30 | Sep 23 | 129 |
| Tizer Gardens | 4,672 | Jun 18 | Jul 3 | Sep 5 | 81 |
| Townsend 3SE | 3,964 | May 19 | Jun 2 | Sep 19 | 122 |
| Trident | 4,036 | May 9 | May 24 | Sep 27 | 139 |
| Trout Creek Rs | 2,356 | May 20 | Jun 9 | Sep 21 | 122 |
| Troy | 1,929 | May 14 | May 31 | Sep 25 | 132 |
| Turner 11N | 2,982 | May 19 | Jun 1 | Sep 21 | 124 |
| Twin Bridges | 4,625 | Jun 8 | Jul 1 | Sep 2 | 82 |
| Valentine | 2,905 | May 18 | May 31 | Sep 21 | 124 |
| Valier | 3,807 | May 17 | May 31 | Sep 24 | 129 |
| Vida 6 NE | 2,284 | May 16 | May 31 | Sep 22 | 129 |
| Virginia City | 5,773 | Jun 4 | Jun 23 | Sep 18 | 106 |
| W Glacier | 3,148 | May 18 | Jun 4 | Sep 20 | 124 |
| Westby | 2,103 | May 18 | May 30 | Sep 21 | 125 |
| Western Ag Rsch Ctr | 3,608 | May 23 | Jun 10 | Sep 21 | 118 |
| White Sulphur Springs #2 | 5,040 | Jun 4 | Jun 20 | Sep 11 | 97 |
| Whitefish | 3,100 | May 16 | Jun 6 | Sep 25 | 129 |
| Wibaux 2 E | 2,696 | May 27 | Jun 13 | Sep 16 | 112 |
| Wilsall 1S | 5,015 | Jun 4 | Jun 23 | Sep 6 | 92 |
| Wilsall 8 ENE | 5,865 | Jun 8 | Jun 30 | Sep 7 | 89 |
| Winifred | 3,243 | May 16 | May 30 | Sep 23 | 127 |
| Wolf Point 29 ENE | 2,085 | May 24 | Jun 6 | Sep 14 | 110 |
| Wolf Point 34 NE | 2,643 | May 13 | May 25 | Sep 28 | 137 |
| Wolf Point Intl Airport | 1,986 | May 16 | May 29 | Sep 20 | 125 |
| Wolf Pt | 2,090 | May 8 | May 20 | Sep 28 | 143 |
| Wyola 1 SW | 3,730 | May 21 | Jun 2 | Sep 17 | 117 |
| Yellowtail Dam | 3,305 | May 7 | May 24 | Oct 5 | 151 |
| Zortman | 4,035 | May 18 | Jun 1 | Sep 23 | 126 |
No station matches that name. Try a nearby town, or look up your ZIP code above.
Last frost and first frost are averages (a 50% chance of frost later in spring or earlier in fall). Safer date is the spring date with only a 10% chance of a later frost.
Using these dates
Plant hardy crops like peas and spinach several weeks before your last frost, and tender crops like tomatoes and peppers after it, once nights stay above 50°F. The Seed Starting Calculator turns your frost date into sowing and planting dates, and When to Plant Tomatoes explains the timing in detail.
Data: NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020, 32°F threshold.
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