North Dakota frost dates
The typical last spring frost ranges from May 10 in Fargo to May 19 in Medora.
4 of the 4 North Dakota cities listed have typical frost dates. The longest frost-free season is 144 days in Grand Forks; the shortest is 123 days in Medora. For a single address, look up your ZIP code: rural ZIPs use their nearest suitable station.
| City | Last spring frost | 1 in 10 after | First fall frost | 1 in 10 before | Hard freeze (28°F) | Season |
|---|---|---|---|---|---|---|
| Bismarck | May 14 | May 27 | Sep 27 | Sep 15 | May 3 / Oct 5 | 136 days |
| Fargo | May 10 | May 23 | Sep 30 | Sep 18 | Apr 30 / Oct 10 | 143 days |
| Grand Forks | May 10 | May 24 | Oct 1 | Sep 20 | Apr 30 / Oct 12 | 144 days |
| Medora | May 19 | Jun 1 | Sep 20 | Sep 6 | May 8 / Sep 29 | 123 days |
Reading the table: Bismarck
In Bismarck, the last spring frost typically comes around May 14: in half of years it is earlier, in half later. In 1 year in 10 it comes after May 27, 13 days later, so tender plants set out after that date have a 90% chance of escaping frost. In fall, the first frost typically arrives around Sep 27, and in 1 year in 10 before Sep 15. Hard freezes (28°F) usually end earlier in spring and start later in fall: around May 3 and Oct 5 in Bismarck.
Frost dates at more North Dakota weather stations
NOAA stations across North Dakota used by our ZIP code lookup, named for the town they are in.
| Station | Elevation | Last spring frost | First fall frost |
|---|---|---|---|
| Ashley | 2,014 ft | May 13 (1 in 10 after May 26) | Sep 28 (before Sep 15) |
| Belcourt Keya Radio | 1,960 ft | May 19 (1 in 10 after Jun 1) | Sep 24 (before Sep 10) |
| Beulah 1 W | 1,785 ft | May 21 (1 in 10 after Jun 3) | Sep 20 (before Sep 5) |
| Bottineau | 1,619 ft | May 15 (1 in 10 after May 28) | Sep 25 (before Sep 13) |
| Bowman | 2,983 ft | May 16 (1 in 10 after May 29) | Sep 25 (before Sep 11) |
| Carrington 4 N | 1,560 ft | May 12 (1 in 10 after May 25) | Sep 27 (before Sep 17) |
| Carson | 2,335 ft | May 19 (1 in 10 after Jun 1) | Sep 25 (before Sep 11) |
| Casselton Agronomy Farm | 935 ft | May 9 (1 in 10 after May 21) | Oct 1 (before Sep 17) |
| Cavalier 7NW | 899 ft | May 12 (1 in 10 after May 27) | Sep 30 (before Sep 17) |
| Colgate | 1,180 ft | May 10 (1 in 10 after May 25) | Sep 24 (before Sep 13) |
| Cooperstown | 1,380 ft | May 17 (1 in 10 after Jun 1) | Sep 23 (before Sep 10) |
| Crosby | 1,959 ft | May 17 (1 in 10 after May 28) | Sep 23 (before Sep 11) |
| Devils Lake Kdlr | 1,464 ft | May 6 (1 in 10 after May 19) | Oct 5 (before Sep 26) |
| Drake 9 Ne | 1,547 ft | May 12 (1 in 10 after May 25) | Sep 27 (before Sep 16) |
| Dunn Ctr 1E | 2,187 ft | May 20 (1 in 10 after Jun 1) | Sep 21 (before Sep 7) |
| Edgeley 3WNW | 1,623 ft | May 7 (1 in 10 after May 20) | Oct 2 (before Sep 21) |
| Edmore 4NW | 1,539 ft | May 15 (1 in 10 after May 31) | Sep 22 (before Sep 11) |
| Edmunds Arrowwood Ref | 1,460 ft | May 11 (1 in 10 after May 25) | Sep 28 (before Sep 16) |
| Enderlin 2W | 1,164 ft | May 3 (1 in 10 after May 16) | Oct 5 (before Sep 23) |
| Fessenden | 1,620 ft | May 13 (1 in 10 after May 26) | Sep 28 (before Sep 15) |
| Flasher | 1,980 ft | May 13 (1 in 10 after May 28) | Sep 27 (before Sep 15) |
| Forman 5 Sse | 1,250 ft | May 7 (1 in 10 after May 20) | Oct 1 (before Sep 18) |
| Fortuna 1 W | 2,350 ft | May 19 (1 in 10 after May 31) | Sep 17 (before Sep 4) |
| Fullerton 1 Ese | 1,435 ft | May 9 (1 in 10 after May 23) | Sep 28 (before Sep 17) |
| Gackle | 1,951 ft | May 6 (1 in 10 after May 19) | Oct 4 (before Sep 23) |
| Garrison | 1,932 ft | May 12 (1 in 10 after May 24) | Sep 30 (before Sep 17) |
| Grafton | 827 ft | May 4 (1 in 10 after May 18) | Oct 7 (before Sep 25) |
| Grand Forks Intl Airport | 842 ft | May 16 (1 in 10 after May 31) | Sep 27 (before Sep 15) |
| Hansboro 4 Nne | 1,540 ft | May 18 (1 in 10 after May 31) | Sep 23 (before Sep 11) |
| Harvey 4NE | 1,611 ft | May 12 (1 in 10 after May 25) | Sep 26 (before Sep 14) |
| Hillsboro 3 N | 910 ft | May 2 (1 in 10 after May 17) | Oct 9 (before Sep 25) |
| Jamestown Muni Airport | 1,494 ft | May 11 (1 in 10 after May 24) | Sep 28 (before Sep 15) |
| Keene 3S | 2,470 ft | May 20 (1 in 10 after Jun 2) | Sep 20 (before Sep 5) |
| Kenmare 1 Wsw | 1,810 ft | May 15 (1 in 10 after May 28) | Sep 23 (before Sep 10) |
| La Moure | 1,334 ft | May 10 (1 in 10 after May 22) | Sep 28 (before Sep 18) |
| Langdon Exp Farm | 1,615 ft | May 17 (1 in 10 after May 30) | Sep 26 (before Sep 13) |
| Leeds | 1,530 ft | May 15 (1 in 10 after May 27) | Sep 27 (before Sep 14) |
| Lidgerwood | 1,125 ft | May 2 (1 in 10 after May 15) | Oct 6 (before Sep 25) |
| Max | 2,110 ft | May 10 (1 in 10 after May 25) | Sep 28 (before Sep 15) |
| Mayville | 983 ft | May 13 (1 in 10 after May 25) | Sep 27 (before Sep 14) |
| Mc Clusky | 1,927 ft | May 8 (1 in 10 after May 20) | Oct 1 (before Sep 19) |
| Mc Henry 3W | 1,555 ft | May 12 (1 in 10 after May 25) | Sep 28 (before Sep 16) |
| Mc Leod 3 E | 1,075 ft | May 6 (1 in 10 after May 19) | Sep 29 (before Sep 18) |
| Minnewaukan | 1,470 ft | May 12 (1 in 10 after May 25) | Sep 29 (before Sep 17) |
| Minot Intl Airport | 1,665 ft | May 10 (1 in 10 after May 22) | Oct 1 (before Sep 19) |
| Mohall | 1,641 ft | May 17 (1 in 10 after May 30) | Sep 23 (before Sep 11) |
| Pembina | 790 ft | May 16 (1 in 10 after May 31) | Sep 29 (before Sep 17) |
| Petersburg 2 N | 1,532 ft | May 11 (1 in 10 after May 25) | Sep 28 (before Sep 16) |
| Rolette 3SE | 1,620 ft | May 22 (1 in 10 after Jun 3) | Sep 20 (before Sep 5) |
| Rugby | 1,550 ft | May 17 (1 in 10 after May 31) | Sep 23 (before Sep 11) |
| Stanley 3 Nnw | 2,280 ft | May 17 (1 in 10 after May 29) | Sep 23 (before Sep 12) |
| Steele 4N | 1,853 ft | May 15 (1 in 10 after May 28) | Sep 25 (before Sep 12) |
| Theodore Roosevelt Airport | 2,580 ft | May 18 (1 in 10 after May 31) | Sep 25 (before Sep 12) |
| Tioga 1E | 2,245 ft | May 11 (1 in 10 after May 24) | Sep 26 (before Sep 13) |
| Tuttle 12NNE | 2,100 ft | May 13 (1 in 10 after May 28) | Sep 29 (before Sep 17) |
| Underwood | 2,045 ft | May 10 (1 in 10 after May 25) | Sep 29 (before Sep 17) |
| Upham 3 N | 1,425 ft | May 15 (1 in 10 after May 26) | Sep 25 (before Sep 13) |
| Valley City 3 Nnw | 1,210 ft | May 13 (1 in 10 after May 25) | Sep 26 (before Sep 14) |
| Wildrose 3NW | 2,227 ft | May 18 (1 in 10 after May 30) | Sep 20 (before Sep 7) |
| Williston Exp Farm | 2,105 ft | May 13 (1 in 10 after May 25) | Sep 26 (before Sep 14) |
32°F dates from NOAA 1991-2020 freeze probabilities for each city's station. "1 in 10 after": a 10% chance of a later spring frost (planting is 90% safe after it). How to read frost dates.