North Dakota frost dates: Last spring and first autumn frost at every NOAA station, 1991-2020
Across North Dakota's 125 NOAA stations with frost dates, the median last spring frost (32°F) runs from May 2 in Hillsboro to May 24 in Hettinger; for half of its places it comes after May 13.
- Typical last spring frost
- May 13median of 92 places
- Typical first autumn frost
- September 27median of 92 places
- Earliest last frost
- May 2Hillsboro
- Latest last frost
- May 24Hettinger
When is the last frost in North Dakota, town by town?
Each date is NOAA's: "after May 13 in half of years" means the last 32°F night of spring came after May 13 in half of the years 1991-2020. By the 1-in-10 date, the last frost has passed in nine years out of ten.
Find your town in the list, or look up a ZIP code for the stations nearest it.
| Place or station | Last frost (median) | 1 in 10 after | First frost (median) | 1 in 10 before | Growing season | Zone |
|---|---|---|---|---|---|---|
| Hillsboro3 mi N | May 2 | May 17 | October 9 | September 25 | 158 days | – |
| Lidgerwood | May 2 | May 15 | October 6 | September 25 | 157 days | 4b |
| Enderlin2 mi W | May 3 | May 16 | October 5 | September 23 | 155 days | 4b |
| Ellendale | May 4 | May 17 | October 2 | September 21 | 149 days | – |
| Fargo (3 mi S) | May 4 | May 18 | October 2 | September 22 | 151 days | – |
| Grafton | May 4 | May 18 | October 7 | September 25 | 156 days | – |
| Devils LakeDevils Lake Kdlr | May 6 | May 19 | October 5 | September 26 | 152 days | – |
| Gackle | May 6 | May 19 | October 4 | September 23 | 150 days | – |
| McLeod (3 mi E) | May 6 | May 19 | September 29 | September 18 | 145 days | 4a |
| Edgeley3 mi WNW | May 7 | May 20 | October 2 | September 21 | 148 days | – |
| Forman5 mi SSE | May 7 | May 20 | October 1 | September 18 | 146 days | 4a |
| Jamestown State Hosp | May 8 | May 21 | September 29 | September 17 | 143 days | 4b |
| McClusky | May 8 | May 20 | October 1 | September 19 | 145 days | 4b |
| Oakes | May 8 | May 21 | September 28 | September 16 | 144 days | – |
| CasseltonCasselton Agronomy Farm | May 9 | May 21 | October 1 | September 17 | 143 days | 4a |
| Fullerton1 mi ESE | May 9 | May 23 | September 28 | September 17 | 141 days | 4a |
| Granville | May 9 | May 22 | October 1 | September 19 | 145 days | – |
| Medora7 mi E | May 9 | May 21 | September 30 | September 15 | 142 days | 4b |
| RichardtonRichardton Abbey | May 9 | May 23 | October 1 | September 18 | 145 days | 4b |
| Watford City | May 9 | May 22 | September 27 | September 15 | 139 days | 4a |
| Bismarck (2.4 mi NNW) | May 10 | May 23 | September 30 | September 16 | 142 days | – |
| Carrington | May 10 | May 23 | September 28 | September 17 | 139 days | – |
| Colgate | May 10 | May 25 | September 24 | September 13 | 136 days | – |
| FargoFargo Hector International Airport | May 10 | May 23 | September 30 | September 18 | 143 days | 4a |
| Grand Forks University (NWS) | May 10 | May 24 | October 1 | September 20 | 144 days | 4a |
| La Moure | May 10 | May 22 | September 28 | September 18 | 140 days | 4a |
| Max | May 10 | May 25 | September 28 | September 15 | 141 days | 4a |
| MinotMinot International Airport | May 10 | May 22 | October 1 | September 19 | 144 days | 4b |
| Underwood | May 10 | May 25 | September 29 | September 17 | 139 days | 4b |
| Center4 mi SE | May 11 | May 26 | September 29 | September 15 | 140 days | – |
| Edmunds Arrowwood Ref | May 11 | May 25 | September 28 | September 16 | 139 days | – |
| Esmond9 mi NNW | May 11 | May 23 | September 28 | September 18 | 138 days | – |
| Foxholm7 mi N | May 11 | May 29 | September 29 | September 13 | 138 days | – |
| JamestownJamestown Municipal Airport | May 11 | May 24 | September 28 | September 15 | 138 days | 4b |
| Larimore4 mi SW | May 11 | May 25 | September 28 | September 16 | 139 days | – |
| Moffit (3 mi SE) | May 11 | May 27 | September 29 | September 15 | 139 days | – |
| Petersburg2 mi N | May 11 | May 25 | September 28 | September 16 | 138 days | 4a |
| Tioga1 mi E | May 11 | May 24 | September 26 | September 13 | 136 days | 3b |
| Wilton | May 11 | May 25 | September 30 | September 17 | 142 days | – |
| Amidon | May 12 | May 28 | September 29 | September 14 | 136 days | – |
| Breien | May 12 | May 27 | September 24 | September 11 | 134 days | – |
| Carrington (4 mi N) | May 12 | May 25 | September 27 | September 17 | 137 days | – |
| Cavalier7 mi NW | May 12 | May 27 | September 30 | September 17 | 139 days | 4a |
| Devils Lake station | May 12 | May 24 | September 30 | September 19 | 141 days | – |
| Drake9 mi NE | May 12 | May 25 | September 27 | September 16 | 137 days | 4a |
| Fairfield | May 12 | May 27 | September 28 | September 13 | 138 days | – |
| Garrison station | May 12 | May 24 | September 30 | September 17 | 140 days | – |
| Harvey4 mi NE | May 12 | May 25 | September 26 | September 14 | 135 days | – |
| Hazelton4 mi NW | May 12 | May 27 | September 27 | September 15 | 136 days | 4a |
| Linton | May 12 | May 26 | September 29 | September 15 | 138 days | – |
| Lisbon | May 12 | May 23 | September 27 | September 14 | 136 days | – |
| McHenry (3 mi W) | May 12 | May 25 | September 28 | September 16 | 139 days | 4a |
| Minnewaukan | May 12 | May 25 | September 29 | September 17 | 138 days | 4a |
| Riverdale | May 12 | May 27 | October 3 | September 20 | 143 days | – |
| Washburn | May 12 | May 25 | September 30 | September 18 | 140 days | – |
| Ashley | May 13 | May 26 | September 28 | September 15 | 137 days | – |
| Fessenden | May 13 | May 26 | September 28 | September 15 | 139 days | – |
| Flasher | May 13 | May 28 | September 27 | September 15 | 135 days | 4a |
| MandanMandan Experiment Station | May 13 | May 26 | September 27 | September 15 | 136 days | 4b |
| Mayville | May 13 | May 25 | September 27 | September 14 | 136 days | – |
| Minot Experiment Station | May 13 | May 26 | September 27 | September 14 | 136 days | 4a |
| Napoleon | May 13 | May 26 | September 28 | September 15 | 136 days | 4a |
| Streeter5 mi NW | May 13 | May 27 | September 30 | September 16 | 139 days | 4a |
| Tuttle (12 mi NNE) | May 13 | May 28 | September 29 | September 17 | 139 days | – |
| Valley City3 mi NNW | May 13 | May 25 | September 26 | September 14 | 136 days | 3b |
| Williston Experiment Farm | May 13 | May 25 | September 26 | September 14 | 135 days | 4a |
| Wishek | May 13 | May 28 | September 27 | September 15 | 135 days | – |
| BismarckBismarck Municipal Airport | May 14 | May 27 | September 27 | September 15 | 136 days | 4a |
| Bismarck Weather Office | May 14 | May 27 | September 30 | September 18 | 138 days | – |
| Garrison | May 14 | May 28 | September 26 | September 13 | 133 days | 4a |
| Heart Butte Dam | May 14 | May 28 | September 29 | September 16 | 136 days | 4a |
| Jamestown (38 mi WSW) | May 14 | May 26 | September 27 | September 15 | 135 days | – |
| Turtle Lake | May 14 | May 26 | September 26 | September 15 | 136 days | 4a |
| Westhope | May 14 | May 26 | September 25 | September 13 | 133 days | 3b |
| Bottineau | May 15 | May 28 | September 25 | September 13 | 133 days | 3b |
| Edmore4 mi NW | May 15 | May 31 | September 22 | September 11 | 128 days | – |
| Kenmare1 mi WSW | May 15 | May 28 | September 23 | September 10 | 129 days | – |
| Leeds | May 15 | May 27 | September 27 | September 14 | 133 days | – |
| Steele4 mi N | May 15 | May 28 | September 25 | September 12 | 133 days | 4a |
| Trotters (3 mi SSE) | May 15 | May 29 | September 25 | September 13 | 132 days | 4a |
| Upham3 mi N | May 15 | May 26 | September 25 | September 13 | 132 days | 3b |
| Beach | May 16 | May 30 | September 26 | September 10 | 130 days | 4a |
| Bowman | May 16 | May 29 | September 25 | September 11 | 132 days | 4b |
| Butte5 mi SE | May 16 | May 31 | September 28 | September 13 | 134 days | – |
| Grand ForksGrand Forks International Airport | May 16 | May 31 | September 27 | September 15 | 133 days | 4a |
| Mott | May 16 | May 30 | September 25 | September 11 | 129 days | – |
| New England | May 16 | May 29 | September 24 | September 10 | 128 days | 4a |
| Pembina | May 16 | May 31 | September 29 | September 17 | 137 days | 4a |
| Almont | May 17 | June 1 | September 21 | September 6 | 124 days | 3b |
| Cooperstown | May 17 | June 1 | September 23 | September 10 | 128 days | 3b |
| Crosby | May 17 | May 28 | September 23 | September 11 | 128 days | 4a |
| Lake Metigoshe State Park | May 17 | May 30 | September 24 | September 12 | 130 days | – |
| LangdonLangdon Experiment Farm | May 17 | May 30 | September 26 | September 13 | 132 days | 3b |
| Mohall | May 17 | May 30 | September 23 | September 11 | 127 days | – |
| Rugby | May 17 | May 31 | September 23 | September 11 | 129 days | 3b |
| Stanley3 mi NNW | May 17 | May 29 | September 23 | September 12 | 127 days | 4a |
| Towner2 mi NE | May 17 | June 1 | September 22 | September 10 | 126 days | 3b |
| Dickinson Ranch Headquarters | May 18 | May 31 | September 24 | September 11 | 127 days | 4b |
| Grassy Butte (2 mi ENE) | May 18 | June 1 | September 23 | September 9 | 125 days | 4b |
| Hansboro4 mi NNE | May 18 | May 31 | September 23 | September 11 | 127 days | – |
| New Salem5 mi NW | May 18 | June 1 | September 24 | September 12 | 127 days | 4a |
| Powers Lake1 mi N | May 18 | June 1 | September 17 | September 4 | 119 days | – |
| Theodore Roosevelt Airport | May 18 | May 31 | September 25 | September 12 | 129 days | 4b |
| Wildrose3 mi NW | May 18 | May 30 | September 20 | September 7 | 124 days | 3b |
| BelcourtBelcourt KEYA Radio | May 19 | June 1 | September 24 | September 10 | 126 days | – |
| Carson | May 19 | June 1 | September 25 | September 11 | 127 days | – |
| Fortuna1 mi W | May 19 | May 31 | September 17 | September 4 | 121 days | 3b |
| Hebron | May 19 | June 2 | September 21 | September 7 | 123 days | 4a |
| Medora station | May 19 | June 1 | September 20 | September 6 | 123 days | – |
| Dickinson | May 20 | June 1 | September 22 | September 8 | 123 days | 4a |
| Dunn Center1 mi E | May 20 | June 1 | September 21 | September 7 | 125 days | – |
| Keene (3 mi S) | May 20 | June 2 | September 20 | September 5 | 121 days | 4a |
| Northgate (5 mi ESE) | May 20 | June 2 | September 19 | September 7 | 121 days | – |
| Pretty Rock | May 20 | June 3 | September 23 | September 8 | 124 days | 4a |
| Rolla1 mi NE | May 20 | May 31 | September 26 | September 14 | 128 days | 4a |
| Beulah1 mi W | May 21 | June 3 | September 20 | September 5 | 121 days | 3b |
| Hettinger Experiment Station | May 21 | June 5 | September 21 | September 5 | 120 days | – |
| Killdeer | May 21 | June 5 | September 23 | September 8 | 124 days | 4a |
| WillistonWilliston Sloulin Field | May 21 | June 3 | September 21 | September 9 | 123 days | 4a |
| Willow City | May 21 | June 1 | September 20 | September 5 | 119 days | 3b |
| Rolette3 mi SE | May 22 | June 3 | September 20 | September 5 | 120 days | – |
| Velva | May 22 | June 3 | September 22 | September 10 | 123 days | 3b |
| Watford City (14 mi S) | May 22 | June 7 | September 17 | September 5 | 119 days | – |
| Taylor7 mi NNW | May 23 | June 5 | September 20 | September 4 | 119 days | 4a |
| HettingerHettinger Municipal Airport | May 24 | June 10 | September 18 | September 1 | 115 days | 4a |
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities, growing-season length); station daily lows via ACIS (zone). Growing season: NOAA's median number of days between the last spring and first autumn 32°F night. Zone: the USDA's plant hardiness rule applied to the station's own 1991-2020 coldest nights.