Frost dates in Idaho
Across 127 NOAA stations in Idaho, the average last spring frost ranges from April 2 at Brownlee Dam to June 22 at Mccall.
| Aberdeen Exp Stn | May 21 | September 20 | 118 |
| American Falls | May 4 | October 8 | 155 |
| American Falls 6 Ne | May 14 | October 2 | 138 |
| Arco | May 22 | September 22 | 119 |
| Arco 17 Sw | May 24 | October 1 | 130 |
| Arrowrock Dam | April 28 | October 14 | 169 |
| Ashton 1N | May 21 | September 21 | 121 |
| Bayview Model Basin | May 22 | September 22 | 122 |
| Bellevue | May 13 | October 2 | 139 |
| Bern | June 17 | September 3 | 77 |
| Blackfoot Fire Dept | May 5 | October 3 | 149 |
| Boise 7 N | May 17 | October 12 | 147 |
| Boise Air Terminal | April 24 | October 21 | 179 |
| Boise Lucky Peak Dam | April 30 | October 22 | 173 |
| Bonners Ferry | April 30 | October 4 | 154 |
| Brownlee Dam | April 2 | November 5 | 216 |
| Bruneau | April 17 | October 17 | 181 |
| Buhl #2 | April 25 | October 15 | 172 |
| Burley Muni Airport | May 7 | October 4 | 150 |
| Cabinet Gorge | May 9 | October 8 | 153 |
| Cambridge | May 15 | September 27 | 134 |
| Cascade 1 Nw | May 30 | September 19 | 110 |
| Castleford 2 N | May 17 | September 29 | 132 |
| Challis Airport | May 14 | September 25 | 131 |
| Chilly Barton Flat | June 14 | September 8 | 86 |
| Coeur D'Alene | April 22 | October 18 | 179 |
| Cottonwood 2 Wsw | May 6 | October 13 | 156 |
| Council | May 10 | October 2 | 145 |
| Craters Of The Moon | June 19 | September 9 | 81 |
| Deer Flat Dam | April 23 | October 18 | 178 |
| Downey | May 31 | September 18 | 110 |
| Driggs | June 13 | September 9 | 86 |
| Dubois Exp Stn | May 18 | September 30 | 132 |
| Dworshak Fish Hatchery | April 20 | October 20 | 182 |
| Elk Rvr | May 16 | September 23 | 128 |
| Emmett 2 E | April 30 | October 17 | 168 |
| Fairfield Rs | June 8 | September 14 | 97 |
| Fenn Rs | April 26 | October 20 | 176 |
| Ft Hall 1 Nne | May 20 | September 20 | 119 |
| Garden Valley | June 1 | September 10 | 102 |
| Gibbonsville #2 | June 1 | September 17 | 107 |
| Glenns Ferry | May 1 | October 3 | 154 |
| Grace | May 29 | September 17 | 111 |
| Grand View 4 Nw | April 28 | October 6 | 162 |
| Grangeville | May 9 | October 3 | 146 |
| Hagerman 2 Sw | May 3 | October 1 | 151 |
| Hamer 4 Nw | June 3 | September 11 | 98 |
| Hazelton | May 7 | October 5 | 149 |
| Hill City 1 W | June 16 | September 6 | 80 |
| Homedale 1 Se | April 24 | October 9 | 169 |
| Howe | May 24 | September 14 | 113 |
| Idaho City | June 17 | September 5 | 80 |
| Idaho Falls - Kifi | May 9 | October 1 | 142 |
| Idaho Falls 16 Se | June 9 | September 11 | 93 |
| Idaho Falls 46 W | June 11 | September 6 | 89 |
| Idaho Falls Fanning Fld | May 23 | September 20 | 114 |
| Jerome | May 2 | October 14 | 166 |
| Jerome Co Airport | May 1 | October 14 | 165 |
| Kamiah | April 29 | October 5 | 163 |
| Kellogg | May 14 | September 26 | 131 |
| Kooskia 5 Sse | April 30 | October 11 | 162 |
| Lava Hot Springs | May 21 | September 21 | 118 |
| Lewiston Nez Perce Co Airport | April 6 | October 26 | 200 |
| Lifton Pumping Stn | May 19 | September 21 | 123 |
| Lowell Three Rivers | April 16 | October 25 | 191 |
| Lowman | June 6 | September 4 | 87 |
| Mackay Lost Rvr Rs | June 1 | September 20 | 109 |
| Malad City | May 22 | September 20 | 116 |
| Malta | June 5 | September 13 | 96 |
| Malta 4 Ese | June 1 | September 19 | 111 |
| Massacre Rocks Sp | May 20 | September 26 | 125 |
| May 2Sse | June 12 | September 6 | 85 |
| Mccall | June 22 | September 2 | 72 |
| Mccall Airport | June 10 | September 10 | 93 |
| Mccammon | May 23 | September 24 | 121 |
| Middle Fork Lodge | May 21 | September 18 | 115 |
| Minidoka Dam | May 16 | October 1 | 136 |
| Monteview | June 12 | September 7 | 87 |
| Mtn Home | May 2 | October 8 | 157 |
| Mullan | May 12 | September 30 | 138 |
| Mullan Pass Vor/Dme | June 10 | September 23 | 104 |
| Murphy 10 W | May 17 | September 30 | 134 |
| Nampa Sugar Factory | April 29 | October 13 | 164 |
| Nezperce | May 24 | September 20 | 116 |
| Oakley | May 15 | October 2 | 137 |
| Ola | May 31 | September 16 | 108 |
| Parma Exp Stn | April 27 | October 9 | 165 |
| Paul 1Ene | May 6 | October 6 | 151 |
| Payette | April 19 | October 20 | 183 |
| Picabo | June 16 | September 9 | 85 |
| Pierce | June 3 | September 7 | 93 |
| Plummer 3 Wsw | May 11 | October 5 | 143 |
| Pocatello 2 Ne | May 16 | October 2 | 137 |
| Pocatello City | May 2 | October 11 | 161 |
| Pocatello Rgnl Airport | May 23 | September 18 | 117 |
| Porthill 1 Sw | May 4 | September 30 | 145 |
| Potlatch 3 Nne | May 15 | September 21 | 126 |
| Powell | May 31 | September 12 | 102 |
| Preston | May 16 | September 28 | 133 |
| Prichard 3 Ese | May 31 | September 5 | 95 |
| Priest Rvr Exp Stn | May 20 | September 13 | 114 |
| Rexburg Byu Idaho | May 12 | September 24 | 132 |
| Rexburg Madison Co Airport | May 15 | September 23 | 129 |
| Reynolds | May 21 | September 28 | 126 |
| Richfield | May 24 | September 26 | 123 |
| Rigby | May 9 | October 5 | 148 |
| Riggins | May 6 | October 9 | 155 |
| Saint Anthony | May 17 | September 22 | 126 |
| Saint Maries | May 3 | October 4 | 152 |
| Salmon-Ksra | May 17 | September 24 | 127 |
| Sandpoint Exp Stn | May 8 | September 28 | 141 |
| Shoshone 1 Wnw | April 24 | October 16 | 173 |
| Shoup | May 3 | October 8 | 157 |
| Silver City 5 W | May 31 | October 6 | 128 |
| Small 6N | June 5 | September 20 | 106 |
| Sugar City | May 29 | September 13 | 106 |
| Swan Falls Ph | April 12 | October 26 | 193 |
| Taylor Rch | May 11 | September 30 | 140 |
| Tetonia Exp Stn | June 15 | September 7 | 85 |
| Twin Falls 6 E | May 6 | October 3 | 150 |
| Twin Falls Sun Vly Rgnl Airport | May 9 | October 4 | 147 |
| Twin Falls-Kmvt | April 30 | October 9 | 161 |
| Wallace | May 5 | October 2 | 149 |
| Weiser | April 23 | October 13 | 174 |
| Winchester | May 23 | September 25 | 121 |
| Yellowpine | June 12 | September 11 | 88 |
| Yellowpine Bar | May 2 | October 10 | 159 |
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