Checking current alerts… View NWS forecast and alerts.
Will it freeze in Williston in the next 7 nights?
The earliest overnight low at or below 32°F in the available NWS frost forecast is Tonight: 29°F (Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST).
Tonight: forecast low 29°F. Freeze.
NWS forecast period: Thu, Nov 5, 6:00 PM CST to Fri, Nov 6, 6:00 AM CST.
5 of the next 7 nights are forecast at 36°F or colder, cold enough for frost on exposed plants.
- Tonight 29°F Freeze · Partly Cloudy
- Fri, Nov 6 33°F Frost possible · Partly Cloudy
- Sat, Nov 7 32°F Freeze · Mostly Clear
- Sun, Nov 8 39°F Above 36°F · Mostly Cloudy
- Mon, Nov 9 31°F Freeze · Partly Cloudy
- Tue, Nov 10 36°F Frost possible · Partly Cloudy
- Wed, Nov 11 37°F Above 36°F · 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 Williston
The median first fall hard-freeze date (28°F) is September 28, from NOAA’s 1991–2020 Climate Normals at Williston Sloulin Intl Airport. 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 18 · May 29 · Jun 16 | Sep 1 · Sep 12 · Sep 23 | 105 days |
| 32°F freeze | May 8 · May 21 · Jun 3 | Sep 9 · Sep 21 · Oct 2 | 123 days |
| 28°F hard freeze | Apr 29 · May 11 · May 25 | Sep 16 · Sep 28 · Oct 11 | 140 days |
Average high temperature by month
1991–2020 normals at Williston Sloulin Intl Airport
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 Williston, ND come from the nearest weather station with freeze statistics in NOAA’s 1991–2020 Climate Normals: Williston Sloulin Intl Airport (station USW00094014, elevation 1,902 ft), 1.2 mi from Williston. 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 Williston
| City | Distance | Last spring frost | First fall frost |
|---|---|---|---|
| Watford City, ND | 32 mi | May 9 | Sep 27 |
| Sidney, MT | 40 mi | May 11 | Sep 27 |
| Dickinson, ND | 98 mi | May 20 | Sep 22 |
| Minot, ND | 109 mi | May 10 | Oct 1 |
| Mandan, ND | 160 mi | May 13 | Sep 27 |
| Miles City, MT | 160 mi | May 8 | Sep 30 |
| Bismarck, ND | 165 mi | May 10 | Sep 30 |
Frequently asked questions
When is the last frost in Williston?
On average, the last spring frost (32°F) in Williston is around May 21. In about 1 year in 10 it comes after June 3, and in 9 years in 10 it comes after May 8.
When is the first frost in Williston?
The first fall frost (32°F) usually arrives around September 21. There’s a 10% chance of a freeze by September 9 and a 90% chance by October 2.
Can it frost in Williston 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 29.
What growing zone is Williston?
Williston 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 58801. See growing zones in North Dakota.
More: all North Dakota frost dates · North Dakota growing zones · UV index today in Williston · frost vs. freeze