USDA Hardiness Zone 4a
Frost Dates for 58538 — Fort Yates, North Dakota
NOAA 1991–2020 normals from Mc Laughlin, SD (2,001 ft), 18 miles south.
Updated
In Fort Yates, the last spring frost (32°F) is around May 12 in half of years and has passed by May 25 in nine years out of ten. The first fall frost comes around September 28, as early as September 16 one year in ten, leaving a typical freeze-free season of 137 days (NOAA, Mc Laughlin, SD).
- Last spring frost
- May 12
- First fall frost
- September 28
- Growing season
- 137 days
- Hardiness zone
- 4a
50% probability
50% probability
freeze-free, 50%
-30 to -25°F (-34.4 to -31.7°C) coldest night
- First snow
- November 26
- Last snow
- March 20
- Winters with snow
- 88%
- Snow per year
- 34.9"
median, 1991–2020
median, 1991–2020
21 of 24 observed
NOAA normal
Frost risk by date in Fort Yates
Half of springs at Mc Laughlin, SD see their last 32°F night by May 12; only one in ten is past it by May 2, and one in ten still has one after May 25. Planting tender crops after May 18 leaves a 30% risk of a frost on them, after May 21 20%, and after May 25 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 21% of the 33 North Dakota stations behind this site's ZIP pages.
In fall the first 32°F night comes by September 28 in half of years, as early as September 16 one year in ten, and holds off past October 9 one year in ten. A hard freeze of 28°F follows 7 days later, around October 5; in spring the one-in-ten date for 28°F is May 16, 9 days before the 32°F one. The freeze-free season lasts 137 days in a typical year, longer than at 52% of the 33 North Dakota stations; it reaches 155 days one year in ten and falls short of 118 one year in ten. On average 186 nights a year drop to 32°F or below. Nights of 36°F, when frost can still settle on leaves in low, open spots, continue 9 days longer, to about May 21, and return around September 20. Severe cold of 16°F or below comes every winter, usually between November 1 and April 5.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 8 | May 12 | May 15 | May 18 | May 21 | May 23 | May 26 | May 30 | Jun 3 |
| 32°F | May 2 | May 4 | May 7 | May 9 | May 12 | May 14 | May 18 | May 21 | May 25 |
| 28°F | Apr 19 | Apr 25 | Apr 29 | May 1 | May 3 | May 5 | May 8 | May 11 | May 16 |
| 24°F | Apr 10 | Apr 14 | Apr 17 | Apr 21 | Apr 24 | Apr 27 | Apr 30 | May 3 | May 8 |
| 20°F | Mar 31 | Apr 4 | Apr 8 | Apr 11 | Apr 14 | Apr 16 | Apr 19 | Apr 24 | Apr 30 |
| 16°F | Mar 19 | Mar 26 | Mar 30 | Apr 2 | Apr 5 | Apr 7 | Apr 11 | Apr 14 | Apr 19 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 9 | Sep 13 | Sep 16 | Sep 18 | Sep 20 | Sep 22 | Sep 25 | Sep 27 | Oct 1 |
| 32°F | Sep 16 | Sep 20 | Sep 23 | Sep 25 | Sep 28 | Sep 30 | Oct 2 | Oct 5 | Oct 9 |
| 28°F | Sep 21 | Sep 26 | Sep 29 | Oct 2 | Oct 5 | Oct 7 | Oct 10 | Oct 14 | Oct 18 |
| 24°F | Sep 28 | Oct 2 | Oct 6 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 23 | Oct 27 |
| 20°F | Oct 6 | Oct 12 | Oct 15 | Oct 20 | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 5 |
| 16°F | Oct 16 | Oct 22 | Oct 26 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 11 | Nov 15 |
Freeze probabilities 1991–2020 at Mc Laughlin, SD, from NOAA NCEI U.S. Climate Normals. Where a temperature is reached in fewer than 99.5% of years, the dates describe only the years that reach it. Not a forecast.
Frost risk on any date in 58538 →Compare Fort Yates with another place →
Weather by month in Fort Yates
July is the warmest month at Mc Laughlin, SD, averaging 85°F by day and 58°F at night; January is the coldest at 24°F and 4°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month.
Warmth for growing adds up to 2,370 growing degree days a year (base 50°F), more than at 85% of the 33 North Dakota stations. 31% of them (724) have built up by the end of June, and July adds the most, 673. Precipitation totals 20.2 inches a year, most in June (3.3") and least in January (0.5"); May to September bring 67% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 24 | 4 | 0.5 | 100% | 31 | 0 |
| Feb | 28 | 7 | 0.5 | 100% | 28 | 0 |
| Mar | 42 | 19 | 0.9 | 100% | 28 | 6 |
| Apr | 56 | 30 | 1.7 | 100% | 18 | 41 |
| May | 68 | 42 | 3.2 | 92% | 4 | 209 |
| Jun | 78 | 53 | 3.3 | 3% | 0 | 468 |
| Jul | 85 | 58 | 3.0 | 0% | 0 | 673 |
| Aug | 84 | 55 | 2.5 | 0% | 0 | 606 |
| Sep | 74 | 45 | 1.5 | 64% | 2 | 304 |
| Oct | 57 | 32 | 1.8 | 100% | 16 | 61 |
| Nov | 41 | 19 | 0.7 | 100% | 28 | 2 |
| Dec | 29 | 9 | 0.6 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Mc Laughlin, SD (2,001 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
Compared with the next station
The nearest other station, Mobridge Municipal Airport, SD, 39 miles southeast of Fort Yates and 286 feet lower, has a last frost 7 days earlier (May 5), a first frost 6 days later (October 4), a season 13 days longer.
When it snows in Fort Yates, North Dakota
The first measurable snow (0.1 inch or more) in Fort Yates usually arrives around November 26, and the last of the season around March 20. Those are the middle dates across the winters of 1991–2020 at Mc Laughlin, SD, 17.7 miles away: half of years saw snow earlier, half later. Snow fell in 88% of those winters. The last 32°F night of spring typically comes 53 days after the last snow.
Planting calendar for 58538
| When | What to do |
|---|---|
| March 3 – March 17 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 17 – March 31 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 14 – April 28 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 12 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 6 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 14 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 28 onward | Plant garlic, mulch beds, lift tender bulbsGarlic wants a cold spell; bare soil loses structure over winter. |
The weeks before and after the 50% dates are general rules of thumb, not NOAA figures; a seed packet gives the timing for each variety.
Where these figures come from
ZIP 58538 is 18 miles from Mc Laughlin, SD, which stands at 2,001 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 58538 in zone 4a, the band where the coldest night of the year averaged -30 to -25°F (-34.4 to -31.7°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across North Dakota →
Hardiness zone and temperature range: USDA Plant Hardiness Zone Map 2023 (USDA-ARS, Oregon State University), ZIP-code listing, unchanged. °C converted from °F by this site.
Thirty-year averages, not a forecast: check the forecast before planting out. How stations are matched and which pages are offered to search engines: methodology.