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Will it freeze in Grand Forks in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Tonight: 24°F (Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST).
Tonight: forecast low 24°F. Hard freeze.
NWS forecast period: Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST.
6 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 24°F Hard freeze · Partly Cloudy
- Fri, Nov 6 27°F Hard freeze · Partly Cloudy
- Sat, Nov 7 32°F Freeze · Mostly Clear
- Sun, Nov 8 38°F Above 36°F · Partly Cloudy
- Mon, Nov 9 32°F Freeze · Mostly Clear
- Tue, Nov 10 30°F Freeze · Partly Cloudy
- Wed, Nov 11 31°F Freeze · Partly Cloudy
Overnight lows from the National Weather Service forecast for this location. This covers the available forecast window, not the first freeze of the whole season. Frost can form above 32°F on clear, calm nights.
Frost and freeze probabilities
Freeze dates shift from year to year. Spring percentages describe the chance of a freeze after the stated date; fall percentages describe the chance of a freeze by that date. The 10% spring date is the cautious one: a later freeze happens about 1 year in 10.
These dates describe historical probabilities, not this year’s forecast or the earliest and latest possible freezes. Different weather stations or probability thresholds can produce different published dates for the same city.
Average first hard freeze in Grand Forks
The median first fall hard-freeze date (28°F) is October 12, from NOAA’s 1991–2020 Climate Normals at Grand Forks University (NWS). This is the 50% probability date, not a forecast for this year.
| Temperature | Last spring date 90% · 50% · 10% chance of a later freeze | First fall date 10% · 50% · 90% chance of an earlier freeze | Season |
|---|---|---|---|
| 36°F frost possible | May 7 · May 19 · Jun 1 | Sep 10 · Sep 23 · Oct 3 | 125 days |
| 32°F freeze | Apr 28 · May 10 · May 24 | Sep 20 · Oct 1 · Oct 15 | 144 days |
| 28°F hard freeze | Apr 16 · Apr 30 · May 14 | Sep 29 · Oct 12 · Oct 25 | 163 days |
Average high temperature by month
1991–2020 normals at Grand Forks University (NWS)
Average low temperature by month
Months with lows near or below freezing carry frost risk
Where these frost dates come from
The frost dates for Grand Forks, ND come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Grand Forks University (NWS) (station USC00323621, elevation 830 ft), 0.5 mi from Grand Forks. Local conditions (valleys, hilltops, distance to water, city heat) can shift frost dates by days or weeks. The hardiness zone is from the 2023 USDA Plant Hardiness Zone Map (USDA ARS and Oregon State University PRISM). See our methodology.
Frost dates near Grand Forks
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| East Grand Forks, MN | 3.7 mi | May 10 | Oct 1 |
| Crookston, MN | 24 mi | May 11 | Sep 27 |
| Thief River Falls, MN | 44 mi | May 14 | Sep 28 |
| Fargo, ND | 74 mi | May 4 | Oct 2 |
| West Fargo, ND | 74 mi | May 4 | Oct 2 |
| Moorhead, MN | 75 mi | May 5 | Oct 3 |
| Horace, ND | 81 mi | May 4 | Oct 2 |
| Valley City, ND | 81 mi | May 13 | Sep 26 |
| Devils Lake, ND | 84 mi | May 6 | Oct 5 |
| Detroit Lakes, MN | 96 mi | May 15 | Sep 24 |
Frequently asked questions
When is the last frost in Grand Forks?
On average, the last spring frost (32°F) in Grand Forks is around May 10. In about 1 year in 10 it comes after May 24, and in 9 years in 10 it comes after April 28.
When is the first frost in Grand Forks?
The first fall frost (32°F) usually arrives around October 1. There’s a 10% chance of a freeze by September 20 and a 90% chance by October 15.
Can it frost in Grand Forks after the last frost date?
Yes. Frost can form on clear, calm nights even when the air stays above 32°F. Temperatures of 36°F or lower, cold enough for frost on exposed plants, have a 50% chance of occurring after May 19.
What growing zone is Grand Forks?
Grand Forks is in USDA Plant Hardiness Zone 4a (average annual extreme minimum temperature −30 to −25°F), based on the 2023 USDA map for ZIP code 58201. See growing zones in North Dakota.
More: all North Dakota frost dates · North Dakota growing zones · UV index today in Grand Forks · frost vs. freeze