Idaho Frost Dates
The median last spring freeze and first fall freeze (32°F) at 127 NOAA stations in Idaho, 1991-2020, with the growing season between them.
Every station
A median date has an even chance of a later freeze in spring or an earlier one in fall. Each town page gives the dates at 36, 32 and 28°F and every probability from 10 to 90 percent.
| Station | Elevation | Last freeze | First freeze | Season, days | Town page |
|---|---|---|---|---|---|
| Aberdeen Exp Stn | 4,405 ft | May 21 | September 20 | 122 | Aberdeen |
| American Falls | 4,510 ft | May 4 | October 8 | 157 | American Falls |
| American Falls 6 Ne | 4,415 ft | May 14 | October 2 | 141 | American Falls |
| Arco | 5,325 ft | May 22 | September 22 | 123 | Arco |
| Arco 17 Sw | 5,920 ft | May 24 | October 1 | 130 | Arco |
| Arrowrock Dam | 3,235 ft | April 28 | October 14 | 169 | Boise |
| Ashton 1N | 5,212 ft | May 21 | September 21 | 123 | Ashton |
| Bayview Model Basin | 2,087 ft | May 22 | September 22 | 123 | Athol |
| Bellevue | 5,192 ft | May 13 | October 2 | 142 | Bellevue |
| Bern | 5,964 ft | June 17 | September 3 | 78 | Montpelier |
| Blackfoot Fire Dept | 4,499 ft | May 5 | October 3 | 151 | Blackfoot |
| Boise 7 N | 3,885 ft | May 17 | October 12 | 148 | Hidden Spring |
| Boise Air Terminal | 2,814 ft | April 24 | October 21 | 180 | Boise |
| Boise Lucky Peak Dam | 2,840 ft | April 30 | October 22 | 175 | Boise |
| Bonners Ferry | 2,075 ft | April 30 | October 4 | 157 | Bonners Ferry |
| Brownlee Dam | 1,844 ft | April 2 | November 5 | 217 | Council |
| Bruneau | 2,530 ft | April 17 | October 17 | 183 | Mountain Home |
| Buhl #2 | 3,800 ft | April 25 | October 15 | 173 | Buhl |
| Burley Muni AP | 4,142 ft | May 7 | October 4 | 150 | Heyburn |
| Cabinet Gorge | 2,173 ft | May 9 | October 8 | 152 | Clark Fork |
| Cambridge | 2,650 ft | May 15 | September 27 | 135 | Council |
| Cascade 1 Nw | 4,896 ft | May 30 | September 19 | 112 | Cascade |
| Castleford 2 N | 3,825 ft | May 17 | September 29 | 135 | Buhl |
| Challis AP | 5,033 ft | May 14 | September 25 | 134 | Challis |
| Chilly Barton Flat | 6,260 ft | June 14 | September 8 | 86 | Sun Valley |
| Coeur D'alene | 2,133 ft | April 22 | October 18 | 179 | Coeur d'Alene |
| Cottonwood 2 Wsw | 3,945 ft | May 6 | October 13 | 160 | Cottonwood |
| Council | 2,943 ft | May 10 | October 2 | 145 | Council |
| Craters Of The Moon | 5,914 ft | June 19 | September 9 | 82 | Arco |
| Deer Flat Dam | 2,510 ft | April 23 | October 18 | 178 | Marsing |
| Downey | 4,865 ft | May 31 | September 18 | 110 | Downey |
| Driggs | 6,120 ft | June 13 | September 9 | 88 | Driggs |
| Dubois Exp Stn | 5,450 ft | May 18 | September 30 | 135 | Dubois |
| Dworshak Fish Hatchery | 995 ft | April 20 | October 20 | 183 | Orofino |
| Elk Rvr | 2,866 ft | May 16 | September 23 | 130 | Deary |
| Emmett 2 E | 2,390 ft | April 30 | October 17 | 170 | Emmett |
| Fairfield RS | 5,065 ft | June 8 | September 14 | 98 | Fairfield |
| Fenn RS | 1,560 ft | April 26 | October 20 | 177 | Kooskia |
| Ft Hall 1 Nne | 4,465 ft | May 20 | September 20 | 123 | Fort Hall |
| Garden Valley | 3,100 ft | June 1 | September 10 | 101 | Horseshoe Bend |
| Gibbonsville #2 | 4,480 ft | June 1 | September 17 | 108 | Salmon |
| Glenns Ferry | 2,466 ft | May 1 | October 3 | 155 | Glenns Ferry |
| Grace | 5,550 ft | May 29 | September 17 | 111 | Grace |
| Grand View 4 Nw | 2,400 ft | April 28 | October 6 | 161 | Murphy |
| Grangeville | 3,300 ft | May 9 | October 3 | 147 | Grangeville |
| Hagerman 2 Sw | 2,897 ft | May 3 | October 1 | 151 | Hagerman |
| Hamer 4 Nw | 4,790 ft | June 3 | September 11 | 100 | Dubois |
| Hazelton | 4,060 ft | May 7 | October 5 | 151 | Hazelton |
| Hill City 1 W | 5,100 ft | June 16 | September 6 | 82 | Fairfield |
| Homedale 1 Se | 2,230 ft | April 24 | October 9 | 168 | Homedale |
| Howe | 4,820 ft | May 24 | September 14 | 113 | Arco |
| Idaho City | 3,965 ft | June 17 | September 5 | 80 | Idaho City |
| Idaho Falls - Kifi | 4,742 ft | May 9 | October 1 | 145 | Lincoln |
| Idaho Falls 16 Se | 5,828 ft | June 9 | September 11 | 94 | Ammon |
| Idaho Falls 46 W | 4,938 ft | June 11 | September 6 | 87 | Arco |
| Idaho Falls Fanning Fld | 4,729 ft | May 23 | September 20 | 120 | Idaho Falls |
| Jerome | 3,740 ft | May 2 | October 14 | 165 | Jerome |
| Jerome CO AP | 4,048 ft | May 1 | October 14 | 166 | Jerome |
| Kamiah | 1,210 ft | April 29 | October 5 | 159 | Kamiah |
| Kellogg | 2,377 ft | May 14 | September 26 | 135 | Kellogg |
| Kooskia 5 Sse | 2,330 ft | April 30 | October 11 | 164 | Kooskia |
| Lava Hot Springs | 4,595 ft | May 21 | September 21 | 123 | McCammon |
| Lewiston Nez Perce CO AP | 1,436 ft | April 6 | October 26 | 203 | Lewiston Orchards |
| Lifton Pumping Stn | 5,935 ft | May 19 | September 21 | 125 | Paris |
| Lowell Three Rivers | 1,480 ft | April 16 | October 25 | 192 | Kooskia |
| Lowman | 3,920 ft | June 6 | September 4 | 90 | Idaho City |
| Mackay Lost Rvr RS | 5,897 ft | June 1 | September 20 | 111 | Arco |
| Malad City | 4,470 ft | May 22 | September 20 | 121 | Malad City |
| Malta | 4,521 ft | June 5 | September 13 | 100 | Oakley |
| Malta 4 Ese | 4,590 ft | June 1 | September 19 | 110 | Rupert |
| Massacre Rocks SP | 4,195 ft | May 20 | September 26 | 129 | American Falls |
| May 2SSE | 5,050 ft | June 12 | September 6 | 86 | Challis |
| Mccall | 5,025 ft | June 22 | September 2 | 72 | McCall |
| Mccall AP | 5,013 ft | June 10 | September 10 | 92 | McCall |
| Mccammon | 4,770 ft | May 23 | September 24 | 124 | McCammon |
| Middle Fork Lodge | 4,480 ft | May 21 | September 18 | 120 | Challis |
| Minidoka Dam | 4,164 ft | May 16 | October 1 | 138 | Rupert |
| Monteview | 4,815 ft | June 12 | September 7 | 87 | Dubois |
| Mtn Home | 3,140 ft | May 2 | October 8 | 159 | Mountain Home |
| Mullan | 3,201 ft | May 12 | September 30 | 141 | Mullan |
| Mullan Pass Vor/dme | 6,028 ft | June 10 | September 23 | 105 | Mullan |
| Murphy 10 W | 3,950 ft | May 17 | September 30 | 136 | Murphy |
| Nampa Sugar Factory | 2,470 ft | April 29 | October 13 | 167 | Nampa |
| Nezperce | 3,248 ft | May 24 | September 20 | 119 | Nezperce |
| Oakley | 4,559 ft | May 15 | October 2 | 140 | Oakley |
| Ola | 3,075 ft | May 31 | September 16 | 108 | Horseshoe Bend |
| Parma Exp Stn | 2,290 ft | April 27 | October 9 | 165 | Parma |
| Paul 1ENE | 4,150 ft | May 6 | October 6 | 153 | Paul |
| Payette | 2,150 ft | April 19 | October 20 | 184 | Payette |
| Picabo | 4,839 ft | June 16 | September 9 | 85 | Carey |
| Pierce | 3,080 ft | June 3 | September 7 | 96 | Kamiah |
| Plummer 3 Wsw | 2,905 ft | May 11 | October 5 | 147 | Plummer |
| Pocatello 2 Ne | 4,832 ft | May 16 | October 2 | 139 | Pocatello |
| Pocatello City | 4,460 ft | May 2 | October 11 | 162 | Pocatello |
| Pocatello Rgnl AP | 4,478 ft | May 23 | September 18 | 118 | Arbon Valley |
| Porthill 1 Sw | 1,799 ft | May 4 | September 30 | 149 | Bonners Ferry |
| Potlatch 3 Nne | 2,760 ft | May 15 | September 21 | 129 | Potlatch |
| Powell | 3,530 ft | May 31 | September 12 | 104 | |
| Preston | 4,719 ft | May 16 | September 28 | 135 | Preston |
| Prichard 3 Ese | 2,547 ft | May 31 | September 5 | 97 | Osburn |
| Priest Rvr Exp Stn | 2,371 ft | May 20 | September 13 | 116 | Priest River |
| Rexburg Byu Idaho | 5,005 ft | May 12 | September 24 | 135 | Rexburg |
| Rexburg Madison CO AP | 4,858 ft | May 15 | September 23 | 131 | Rexburg |
| Reynolds | 3,930 ft | May 21 | September 28 | 130 | Murphy |
| Richfield | 4,309 ft | May 24 | September 26 | 125 | Shoshone |
| Rigby | 4,856 ft | May 9 | October 5 | 149 | Rigby |
| Riggins | 2,056 ft | May 6 | October 9 | 156 | McCall |
| Saint Anthony | 4,910 ft | May 17 | September 22 | 128 | Saint Anthony |
| Saint Maries | 2,151 ft | May 3 | October 4 | 154 | Saint Maries |
| Salmon-Ksra | 3,953 ft | May 17 | September 24 | 130 | Salmon |
| Sandpoint Exp Stn | 2,126 ft | May 8 | September 28 | 143 | Sandpoint |
| Shoshone 1 Wnw | 3,950 ft | April 24 | October 16 | 175 | Shoshone |
| Shoup | 3,400 ft | May 3 | October 8 | 158 | Salmon |
| Silver City 5 W | 6,160 ft | May 31 | October 6 | 128 | Murphy |
| Small 6N | 5,740 ft | June 5 | September 20 | 107 | Dubois |
| Sugar City | 4,925 ft | May 29 | September 13 | 107 | Sugar City |
| Swan Falls Ph | 2,325 ft | April 12 | October 26 | 197 | Murphy |
| Taylor Rch | 3,835 ft | May 11 | September 30 | 142 | Salmon |
| Tetonia Exp Stn | 6,170 ft | June 15 | September 7 | 84 | Driggs |
| Twin Falls 6 E | 3,960 ft | May 6 | October 3 | 150 | Kimberly |
| Twin Falls Sun Vly Rgnl AP | 4,151 ft | May 9 | October 4 | 148 | Twin Falls |
| Twin Falls-Kmvt | 3,670 ft | April 30 | October 9 | 162 | Twin Falls |
| Wallace | 2,710 ft | May 5 | October 2 | 150 | Wallace |
| Weiser | 2,120 ft | April 23 | October 13 | 173 | Weiser |
| Winchester | 3,972 ft | May 23 | September 25 | 125 | Lapwai |
| Yellowpine | 5,050 ft | June 12 | September 11 | 91 | McCall |
| Yellowpine Bar | 2,480 ft | May 2 | October 10 | 161 | Grangeville |
Sources
NOAA NCEI U.S. Climate Normals, 1991-2020, annual and seasonal freeze probabilities. Public domain.