Montana Frost Dates

Montana has 245 NOAA weather stations with freeze records in the 1991–2020 climate normals. The typical last spring frost ranges from April 30 at Norris Madison Pwr House to June 18 at Tizer Gardens; at half the stations it has come by May 20. The first fall frost typically arrives between September 2 at Opheim 12 Sse and October 15 at Bigfork 13 S, with a median of September 21.

The growing season between the typical frosts runs from 77 days at Lewistown 42 Wsw to 165 days at Bigfork 13 S; 123 days at the median station.

At 29 stations, a freeze is possible in any month.

Every station in Montana

Typical dates have a 50% chance of a frost after them in spring, and before them in fall; safer dates, 10%. A garden can differ from its nearest station, especially in a valley or on a hillside: see why your garden may differ.

Montana: freeze (32 °F) dates by NOAA station, 1991–2020 normals
Station	Elevation	Last frost	Safer	First frost	Safer	Season (days)
Adel	5,017 ft	Jun 4	Jun 22	Sep 12	Aug 26	98
Alberton	3,060 ft	May 18	Jun 6	Sep 25	Sep 7	126
Albion 1 N	3,312 ft	Jun 2	Jun 21	Sep 6	Aug 23	95
Alder 17 S	5,850 ft	Jun 6	Jun 25	Sep 14	Aug 31	98
Alder 19s	5,749 ft	A freeze is possible in any month
Anaconda	5,230 ft	Jun 1	Jun 25	Sep 14	Aug 31	105
Augusta	4,070 ft	May 19	May 31	Sep 21	Sep 4	125
Austin 1 W	4,851 ft	Jun 4	Jun 18	Sep 14	Aug 30	100
Baker Muni Ap	2,971 ft	May 16	May 29	Sep 26	Sep 11	132
Baker	2,933 ft	May 12	May 27	Sep 26	Sep 11	135
Biddle 8 Sw	3,631 ft	May 14	May 27	Sep 28	Sep 13	134
Big Sandy	2,770 ft	May 17	Jun 4	Sep 25	Sep 12	128
Big Sky 2wnw	6,590 ft	A freeze is possible in any month
Big Timber	4,100 ft	May 14	May 27	Sep 26	Sep 10	133
Bigfork 13 S	2,979 ft	May 1	May 16	Oct 15	Sep 30	165
Billings Logan Intl Ap	3,581 ft	May 4	May 18	Oct 7	Sep 26	156
Billings Wfo	3,185 ft	May 5	May 21	Oct 3	Sep 20	149
Billings Wtp	3,097 ft	May 10	May 24	Oct 1	Sep 19	142
Blackleaf	4,235 ft	Jun 9	Jul 2	Sep 3	Aug 19	86
Boulder	4,904 ft	Jun 7	Jun 25	Sep 8	Aug 25	90
Bozeman 6 W Exp Farm	4,775 ft	May 23	Jun 12	Sep 23	Sep 4	123
Bozeman Gallatin Fld	4,427 ft	May 26	Jun 12	Sep 16	Sep 2	112
Bozeman Montana State Univ	4,913 ft	May 26	Jun 14	Sep 22	Sep 5	116
Brady 27 Ene (The Knees)	3,325 ft	May 13	May 29	Sep 29	Sep 16	137
Brandenberg	2,770 ft	May 18	May 30	Sep 22	Sep 8	126
Bredette	2,313 ft	May 20	Jun 1	Sep 21	Sep 6	122
Bridger 2 N	3,583 ft	May 14	May 30	Sep 24	Sep 7	129
Broadus	3,032 ft	May 16	May 29	Sep 28	Sep 13	135
Brockway 3 Wsw	2,630 ft	May 20	Jun 5	Sep 19	Sep 4	121
Busby	3,430 ft	May 23	Jun 7	Sep 15	Sep 1	113
Butte Bert Mooney Ap	5,506 ft	Jun 13	Jul 1	Sep 5	Aug 24	83
Bynum 4 Sse	4,039 ft	May 16	May 28	Sep 27	Sep 16	133
Carlyle 13 Nw	3,145 ft	May 18	May 31	Sep 29	Sep 13	134
Carter 14 W	3,450 ft	May 23	Jun 9	Sep 23	Sep 8	120
Cascade 20 Sse	4,600 ft	A freeze is possible in any month
Cascade 5 S	3,360 ft	May 21	Jun 6	Sep 19	Sep 2	120
Chester	3,132 ft	May 24	Jun 9	Sep 17	Sep 3	115
Chinook 35se	3,360 ft	May 23	Jun 3	Sep 23	Sep 11	121
Chinook	2,420 ft	May 14	May 27	Sep 23	Sep 11	130
Choteau 8ne	3,741 ft	May 20	Jun 4	Sep 22	Sep 8	123
Choteau	3,845 ft	May 28	Jun 20	Sep 12	Aug 30	104
Circle	2,480 ft	May 17	May 31	Sep 22	Sep 7	126
Cohagen	2,720 ft	May 25	Jun 9	Sep 14	Aug 31	110
Colstrip	3,218 ft	May 15	May 28	Sep 30	Sep 15	138
Columbus	3,602 ft	May 27	Jun 12	Sep 14	Sep 1	108
Conrad	3,550 ft	May 20	Jun 3	Sep 19	Sep 4	119
Content 4 Nne	2,325 ft	May 25	Jun 8	Sep 14	Aug 29	110
Cooke City 2 W	7,483 ft	A freeze is possible in any month
Creston	2,935 ft	May 12	May 26	Sep 25	Sep 9	134
Culbertson	1,940 ft	May 21	Jun 3	Sep 20	Sep 6	120
Cut Bank Muni Ap	3,838 ft	May 24	Jun 5	Sep 15	Sep 1	113
Darby	3,880 ft	May 24	Jun 14	Sep 23	Sep 4	118
Deer Lodge 3 W	4,850 ft	A freeze is possible in any month
Del Bonita	4,337 ft	May 28	Jun 12	Sep 16	Aug 28	110
Denton	3,610 ft	Jun 1	Jun 26	Sep 11	Aug 29	101
Dillon 18 Wsw	5,971 ft	A freeze is possible in any month
Dillon Ap	5,200 ft	Jun 2	Jun 21	Sep 13	Aug 30	101
Dillon U Of Montana Western	5,129 ft	Jun 5	Jun 23	Sep 13	Aug 29	98
Divide	5,350 ft	Jun 10	Jul 2	Sep 7	Aug 24	85
Drummond Aviation	4,000 ft	A freeze is possible in any month
Dunkirk 19nne	3,323 ft	May 23	Jun 8	Sep 14	Sep 1	112
E Glacier	4,806 ft	Jun 8	Jul 1	Sep 5	Aug 20	88
Ekalaka	3,432 ft	May 20	Jun 1	Sep 23	Sep 7	126
Elliston	5,080 ft	Jun 9	Jun 26	Sep 8	Aug 26	91
Ennis	4,953 ft	Jun 16	Jul 6	Sep 4	Aug 20	78
Eureka Rs	2,532 ft	May 11	May 25	Sep 27	Sep 10	138
Fairfield	3,983 ft	May 13	Jun 1	Sep 27	Sep 14	135
Flatwillow 4 Ene	3,292 ft	May 16	May 31	Sep 28	Sep 15	132
Forsyth	2,515 ft	May 9	May 21	Sep 29	Sep 16	142
Fortine 1 N	3,000 ft	May 16	Jun 3	Sep 18	Sep 1	121
Ft Assiniboine	2,675 ft	May 15	May 28	Sep 24	Sep 8	130
Ft Belknap 2 Sw	2,527 ft	May 16	May 28	Sep 22	Sep 10	128
Ft Benton	2,649 ft	May 15	May 30	Sep 22	Sep 7	129
Ft Peck Pwr Plt	2,071 ft	May 8	May 20	Oct 1	Sep 18	145
Gardiner	5,275 ft	May 21	Jun 9	Sep 27	Sep 12	128
Geraldine	3,145 ft	May 14	May 28	Sep 26	Sep 13	134
Gibson 2 Ne	4,444 ft	May 27	Jun 12	Sep 18	Sep 3	113
Gibson Dam	4,590 ft	Jun 12	Jul 5	Sep 8	Aug 23	88
Gildford	2,820 ft	May 24	Jun 7	Sep 15	Aug 29	114
Glasgow #2	2,090 ft	May 3	May 15	Oct 1	Sep 19	151
Glasgow Intl Ap	2,285 ft	May 6	May 18	Sep 30	Sep 17	145
Glen 4 N	5,054 ft	A freeze is possible in any month
Glendive	2,075 ft	May 3	May 16	Oct 4	Sep 22	153
Goldbutte 7 N	3,498 ft	A freeze is possible in any month
Grass Range	3,490 ft	May 20	Jun 6	Sep 24	Sep 11	126
Great Falls 16st	3,505 ft	May 6	May 19	Oct 1	Sep 17	147
Great Falls Intl Ap	3,664 ft	May 19	Jun 2	Sep 24	Sep 9	126
Great Falls Wfo	3,705 ft	May 12	May 27	Sep 28	Sep 14	138
Hamilton	3,585 ft	May 21	Jun 6	Sep 22	Sep 6	122
Hardin	2,880 ft	May 13	May 26	Sep 29	Sep 14	135
Harlem 20s	2,695 ft	May 24	Jun 11	Sep 22	Sep 8	118
Harlem	2,371 ft	May 16	May 31	Sep 21	Sep 8	125
Harlowton 11nw	4,954 ft	May 30	Jun 17	Sep 20	Sep 4	110
Harlowton	4,222 ft	May 23	Jun 6	Sep 16	Sep 1	113
Haugan 1 W	3,160 ft	A freeze is possible in any month
Havre City Co Ap	2,585 ft	May 15	May 27	Sep 23	Sep 11	129
Hebgen Dam	6,489 ft	Jun 15	Jul 7	Sep 10	Aug 25	87
Helena Rgnl Ap	3,828 ft	May 9	May 25	Sep 30	Sep 17	142
Heron 2 Nw	2,240 ft	May 20	Jun 5	Sep 20	Sep 1	119
Highwood 7 Ne	3,600 ft	May 7	May 21	Oct 2	Sep 19	149
Hinsdale 4 Sw	2,805 ft	May 15	May 30	Sep 26	Sep 12	132
Holter Dam	3,487 ft	May 19	Jun 8	Sep 24	Sep 6	124
Hungry Horse Dam	3,160 ft	May 9	May 30	Oct 1	Sep 13	141
Huntley Exp Stn	3,034 ft	May 12	May 26	Sep 25	Sep 13	136
Hysham 25 Sse	3,100 ft	May 26	Jun 13	Sep 16	Sep 1	111
Hysham	2,669 ft	May 10	May 22	Sep 29	Sep 15	141
Ingomar 9 E	2,800 ft	May 21	Jun 4	Sep 19	Sep 6	120
Jackson	6,480 ft	A freeze is possible in any month
Joliet	3,838 ft	May 29	Jun 17	Sep 15	Sep 1	107
Joplin	3,323 ft	May 21	Jun 6	Sep 19	Sep 3	119
Jordan Ap	2,662 ft	May 18	May 31	Sep 20	Sep 8	123
Jordan	2,620 ft	May 21	Jun 2	Sep 18	Sep 4	118
Judith Gap 13 E	4,791 ft	Jun 3	Jun 25	Sep 15	Aug 29	100
Judith Gap	4,630 ft	Jun 1	Jun 16	Sep 15	Aug 31	104
Kalispell Glacier Ap	2,957 ft	May 31	Jun 22	Sep 10	Aug 26	100
Lakeview	6,710 ft	A freeze is possible in any month
Laurin 2ne	5,198 ft	May 24	Jun 13	Sep 22	Sep 6	117
Lennep 5 Sw	5,600 ft	A freeze is possible in any month
Lewistown 11 Sse	4,965 ft	May 31	Jun 18	Sep 14	Aug 30	105
Lewistown 11ese	5,028 ft	May 19	Jun 1	Sep 25	Sep 11	128
Lewistown 42 Wsw	5,070 ft	Jun 15	Jul 8	Sep 4	Aug 19	77
Lewistown Muni Ap	4,145 ft	May 23	Jun 8	Sep 21	Sep 8	119
Lewistown	3,911 ft	May 14	May 27	Sep 28	Sep 14	135
Libby 1 Ne Rs	2,096 ft	May 23	Jun 7	Sep 21	Sep 3	120
Libby 32 Sse	3,440 ft	A freeze is possible in any month
Libby Dam (Base)	2,110 ft	May 11	May 27	Oct 1	Sep 14	142
Libby	2,140 ft	May 10	May 26	Sep 26	Sep 11	137
Lima	6,279 ft	Jun 11	Jun 30	Sep 10	Aug 27	89
Lincoln Rs	4,575 ft	A freeze is possible in any month
Lindbergh Lake	4,320 ft	May 20	Jun 7	Sep 22	Sep 5	120
Livingston 12 S	5,044 ft	May 19	Jun 11	Sep 25	Sep 7	125
Livingston Mission Fld	4,643 ft	May 27	Jun 14	Sep 14	Aug 27	108
Logan Landfill	4,243 ft	May 26	Jun 12	Sep 15	Sep 1	111
Loma	2,578 ft	May 20	Jun 3	Sep 19	Sep 4	120
Malta 35 S	2,615 ft	May 16	May 29	Sep 23	Sep 10	128
Malta 7 E	2,231 ft	May 7	May 21	Sep 28	Sep 14	143
Malta	2,262 ft	May 10	May 22	Sep 29	Sep 17	139
Martinsdale 3 Nnw	4,800 ft	Jun 3	Jun 25	Sep 8	Aug 23	94
Medicine Lake 3 Se	1,942 ft	May 16	May 30	Sep 18	Sep 7	125
Melstone	2,932 ft	May 10	May 23	Sep 29	Sep 14	141
Melville 4 W	5,365 ft	Jun 9	Jun 27	Sep 7	Aug 21	88
Mildred 5 N	2,482 ft	May 20	Jun 2	Sep 22	Sep 7	124
Miles City F Wiley Fld	2,624 ft	May 8	May 21	Sep 30	Sep 17	144
Millegan 14 Se	4,970 ft	Jun 11	Jul 3	Sep 6	Aug 20	86
Missoula 2 Ne	3,420 ft	May 10	May 28	Oct 1	Sep 16	143
Missoula 6 Nw Wfo	3,197 ft	May 6	May 19	Oct 4	Sep 23	151
Missoula Intl Ap	3,192 ft	May 16	Jun 1	Sep 26	Sep 12	130
Mizpah 4 Nnw	2,480 ft	May 22	Jun 7	Sep 15	Sep 2	117
Moccasin Exp Stn	4,300 ft	May 28	Jun 19	Sep 20	Sep 4	112
Moorhead 9 Ne	3,220 ft	May 17	May 31	Sep 22	Sep 7	126
Mosby 4 Ene	2,910 ft	May 5	May 26	Oct 4	Sep 22	151
Mystic Lake	6,544 ft	Jun 5	Jun 21	Sep 14	Aug 31	99
Nashua #2	2,067 ft	May 12	May 26	Sep 24	Sep 12	134
Neihart 8 Nnw	5,230 ft	Jun 6	Jun 28	Sep 12	Aug 29	99
Norris Madison Pwr House	4,745 ft	Apr 30	May 14	Oct 10	Sep 27	162
Nye #2	4,840 ft	Jun 1	Jun 21	Sep 11	Aug 25	100
Olney	3,165 ft	A freeze is possible in any month
Opheim 10 N	2,878 ft	Jun 1	Jun 18	Sep 7	Aug 24	99
Opheim 12 Sse	2,936 ft	Jun 5	Jun 23	Sep 2	Aug 15	89
Ovando 9 Sse	4,325 ft	A freeze is possible in any month
Phillipsburg Rs	5,270 ft	A freeze is possible in any month
Plentywood	2,048 ft	May 25	Jun 8	Sep 14	Sep 2	111
Plevna	2,780 ft	May 21	Jun 4	Sep 20	Sep 5	121
Polebridge	3,520 ft	A freeze is possible in any month
Polson	3,010 ft	May 10	May 26	Oct 5	Sep 22	147
Pompeys Pillar 15n	3,390 ft	May 22	Jun 7	Sep 22	Sep 7	121
Port Of Morgan	2,830 ft	May 19	Jun 2	Sep 22	Sep 9	124
Potomac	3,690 ft	A freeze is possible in any month
Powderville 8 Nne	2,800 ft	May 13	May 31	Sep 25	Sep 6	132
Rapelje	4,068 ft	May 24	Jun 11	Sep 21	Sep 4	116
Raymond Border Stn	2,345 ft	May 19	Jun 1	Sep 23	Sep 11	125
Raynesford 2 Nnw	4,215 ft	May 22	Jun 9	Sep 23	Sep 7	123
Red Lodge	5,646 ft	Jun 3	Jun 18	Sep 19	Aug 31	106
Redstone	2,106 ft	May 28	Jun 13	Sep 7	Aug 22	101
Ridgeway 1 S	3,316 ft	May 17	Jun 1	Sep 22	Sep 5	127
Rock Springs	3,024 ft	May 15	May 27	Sep 25	Sep 10	132
Rogers Pass 9 Nne	4,200 ft	May 21	Jun 8	Sep 15	Aug 30	115
Roundup 15 Sw	3,386 ft	May 22	Jun 4	Sep 15	Aug 31	114
Roundup	3,200 ft	May 20	Jun 2	Sep 21	Sep 5	124
Roy 8 Ne	3,085 ft	May 14	May 29	Sep 24	Sep 12	134
Rudyard 19s	2,878 ft	May 23	Jun 3	Sep 19	Sep 5	119
Rudyard 21 N	3,000 ft	May 30	Jun 15	Sep 11	Aug 27	103
Ryegate 18 Nnw	4,440 ft	May 26	Jun 13	Sep 18	Sep 1	112
Ryegate	3,650 ft	May 17	May 30	Sep 23	Sep 10	127
Saco 1 Nnw	2,185 ft	May 15	May 26	Sep 23	Sep 11	130
Saint Ignatius	2,915 ft	May 12	Jun 1	Oct 2	Sep 19	142
Saint Regis 1 Ne	2,660 ft	A freeze is possible in any month
Sand Creek	2,910 ft	May 12	May 27	Sep 27	Sep 14	136
Savage	1,978 ft	May 12	May 26	Sep 25	Sep 12	135
Scobey 4 Nw	2,390 ft	May 28	Jun 13	Sep 6	Aug 24	99
Seeley Lake Rs	4,100 ft	A freeze is possible in any month
Shelby	3,325 ft	May 23	Jun 6	Sep 16	Sep 3	115
Shonkin 7 S	4,300 ft	May 24	Jun 10	Sep 21	Aug 31	119
Sidney	1,933 ft	May 11	May 25	Sep 27	Sep 13	137
Silver Gate	7,495 ft	A freeze is possible in any month
Simpson 6 N - Wildhorse	2,815 ft	May 26	Jun 8	Sep 15	Sep 1	110
Skq Dam	2,730 ft	May 15	Jun 1	Sep 28	Sep 13	134
Sonnette 7 Sw	3,914 ft	May 25	Jun 7	Sep 19	Sep 1	115
St Marie	2,756 ft	May 13	May 26	Sep 27	Sep 13	134
St Mary	4,560 ft	Jun 12	Jul 3	Sep 5	Aug 18	82
St. Mary 1 Ssw	4,555 ft	Jun 3	Jun 23	Sep 8	Aug 22	94
Stanford	4,860 ft	May 25	Jun 15	Sep 21	Sep 6	118
Stevensville	3,375 ft	May 22	Jun 13	Sep 19	Sep 3	115
Sula 14 Ne	5,155 ft	A freeze is possible in any month
Sula 3 Ene	4,475 ft	A freeze is possible in any month
Sun Rvr 4 S	3,600 ft	Jun 2	Jun 21	Sep 10	Aug 25	96
Sunburst 8 E	3,700 ft	May 17	May 31	Sep 25	Sep 9	129
Superior	2,710 ft	May 17	Jun 8	Sep 23	Sep 6	125
Swan Lake	3,100 ft	May 17	Jun 4	Sep 19	Sep 4	121
Sweetgrass	3,510 ft	May 15	May 28	Sep 25	Sep 11	132
Terry 21 Nnw	3,142 ft	May 26	Jun 13	Sep 17	Sep 1	113
Terry	2,250 ft	May 12	May 25	Sep 28	Sep 13	137
Thompson Falls Ph	2,380 ft	May 7	May 19	Oct 4	Sep 21	150
Tiber Dam	2,850 ft	May 16	May 30	Sep 23	Sep 9	129
Tizer Gardens	4,672 ft	Jun 18	Jul 3	Sep 5	Aug 21	81
Townsend 3se	3,964 ft	May 19	Jun 2	Sep 19	Sep 5	122
Trident	4,036 ft	May 9	May 24	Sep 27	Sep 12	139
Trout Creek Rs	2,356 ft	May 20	Jun 9	Sep 21	Sep 2	122
Troy	1,929 ft	May 14	May 31	Sep 25	Sep 9	132
Turner 11n	2,982 ft	May 19	Jun 1	Sep 21	Sep 8	124
Twin Bridges	4,625 ft	Jun 8	Jul 1	Sep 2	Aug 16	82
Valentine	2,905 ft	May 18	May 31	Sep 21	Sep 7	124
Valier	3,807 ft	May 17	May 31	Sep 24	Sep 11	129
Vida 6 Ne	2,284 ft	May 16	May 31	Sep 22	Sep 10	129
Virginia City	5,773 ft	Jun 4	Jun 23	Sep 18	Sep 3	106
W Glacier	3,148 ft	May 18	Jun 4	Sep 20	Sep 3	124
W Yellowstone Gateway	6,679 ft	A freeze is possible in any month
Westby	2,103 ft	May 18	May 30	Sep 21	Sep 7	125
Western Ag Rsch Ctr	3,608 ft	May 23	Jun 10	Sep 21	Sep 5	118
White Sulphur Springs #2	5,040 ft	Jun 4	Jun 20	Sep 11	Aug 27	97
Whitefish	3,100 ft	May 16	Jun 6	Sep 25	Sep 8	129
Wibaux 2 E	2,696 ft	May 27	Jun 13	Sep 16	Sep 2	112
Wilsall 1s	5,015 ft	Jun 4	Jun 23	Sep 6	Aug 28	92
Wilsall 8 Ene	5,865 ft	Jun 8	Jun 30	Sep 7	Aug 21	89
Winifred	3,243 ft	May 16	May 30	Sep 23	Sep 9	127
Wisdom	6,060 ft	A freeze is possible in any month
Wise Rvr 3 Wnw	5,730 ft	A freeze is possible in any month
Wolf Point 29 Ene	2,085 ft	May 24	Jun 6	Sep 14	Sep 1	110
Wolf Point 34 Ne	2,643 ft	May 13	May 25	Sep 28	Sep 14	137
Wolf Point Intl Ap	1,986 ft	May 16	May 29	Sep 20	Sep 7	125
Wolf Pt	2,090 ft	May 8	May 20	Sep 28	Sep 15	143
Wyola 1 Sw	3,730 ft	May 21	Jun 2	Sep 17	Sep 5	117
Yaak 9nne	3,085 ft	A freeze is possible in any month
Yellowtail Dam	3,305 ft	May 7	May 24	Oct 5	Sep 20	151
Zortman	4,035 ft	May 18	Jun 1	Sep 23	Sep 7	126

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Questions

When is the last frost in Montana?

It depends on where you are. The typical last spring frost at Montana's NOAA stations ranges from April 30 to June 18, and half of them have had it by May 20. Enter your ZIP code above for the station nearest you.

When is the first frost in Montana?

Typically between September 2 and October 15, depending on the station; the median is September 21. Plan fall crops back from your own station's date.

What do "typical" and "safer" mean?

With the typical (50%) last-frost date, half of years still have a frost after it. With the safer (10%) date, only one year in ten does. In fall it's the other way around: the safer date is the earlier one.

Sources

NOAA National Centers for Environmental Information, U.S. Climate Normals 1991–2020 (annual/seasonal, by station: freeze dates at 32 °F)

Montana Frost Dates

Every station in Montana

Plan your garden with these dates

Questions

Other states

Sources