USDA Hardiness Zone 4a
Frost Dates for 58523 — Beulah, North Dakota
NOAA 1991–2020 normals from Beulah 1 W, ND (1,785 ft), 3 miles northwest.
Updated
In Beulah, the last spring frost (32°F) is around May 21 in half of years and has passed by June 3 in nine years out of ten. The first fall frost comes around September 20, as early as September 5 one year in ten, leaving a typical freeze-free season of 121 days (NOAA, Beulah 1 W, ND).
- Last spring frost
- May 21
- First fall frost
- September 20
- Growing season
- 121 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
- October 31
- Last snow
- April 4
- Winters with snow
- 100%
- Snow per year
- —
median, 1991–2020
median, 1991–2020
17 of 17 observed
NOAA normal
Frost risk by date in Beulah
Half of springs at Beulah 1 W, ND see their last 32°F night by May 21; only one in ten is past it by May 7, and one in ten still has one after June 3. Planting tender crops after May 26 leaves a 30% risk of a frost on them, after May 30 20%, and after June 3 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 20 in half of years, as early as September 5 one year in ten, and holds off past October 4 one year in ten. A hard freeze of 28°F follows 8 days later, around September 28; in spring the one-in-ten date for 28°F is May 25, 9 days before the 32°F one. The freeze-free season lasts 121 days in a typical year, the shortest of the 33 North Dakota stations; it reaches 141 days one year in ten and falls short of 99 one year in ten. On average 191 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 10 days longer, to about May 31, and return around September 10. Severe cold of 16°F or below comes every winter, usually between October 29 and April 11.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 18 | May 22 | May 25 | May 28 | May 31 | Jun 2 | Jun 5 | Jun 9 | Jun 17 |
| 32°F | May 7 | May 12 | May 15 | May 18 | May 21 | May 24 | May 26 | May 30 | Jun 3 |
| 28°F | Apr 27 | May 1 | May 4 | May 7 | May 11 | May 13 | May 16 | May 20 | May 25 |
| 24°F | Apr 14 | Apr 19 | Apr 24 | Apr 28 | Apr 30 | May 3 | May 6 | May 10 | May 15 |
| 20°F | Apr 6 | Apr 10 | Apr 13 | Apr 16 | Apr 19 | Apr 23 | Apr 26 | Apr 30 | May 5 |
| 16°F | Mar 27 | Apr 2 | Apr 5 | Apr 8 | Apr 11 | Apr 14 | Apr 17 | Apr 20 | Apr 26 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Aug 24 | Aug 31 | Sep 4 | Sep 7 | Sep 10 | Sep 13 | Sep 15 | Sep 19 | Sep 23 |
| 32°F | Sep 5 | Sep 10 | Sep 14 | Sep 17 | Sep 20 | Sep 22 | Sep 25 | Sep 29 | Oct 4 |
| 28°F | Sep 14 | Sep 19 | Sep 22 | Sep 25 | Sep 28 | Oct 1 | Oct 4 | Oct 8 | Oct 14 |
| 24°F | Sep 22 | Sep 27 | Oct 1 | Oct 5 | Oct 8 | Oct 12 | Oct 16 | Oct 21 | Oct 28 |
| 20°F | Oct 1 | Oct 7 | Oct 12 | Oct 16 | Oct 20 | Oct 24 | Oct 27 | Oct 30 | Nov 3 |
| 16°F | Oct 10 | Oct 17 | Oct 22 | Oct 26 | Oct 29 | Nov 1 | Nov 3 | Nov 6 | Nov 10 |
Freeze probabilities 1991–2020 at Beulah 1 W, ND, 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 58523 →Compare Beulah with another place →
Weather by month in Beulah
July is the warmest month at Beulah 1 W, ND, averaging 86°F by day and 56°F at night; January is the coldest at 23°F and 3°F. A freezing night is all but certain in every month from October to May (a 90% chance or more). From July to August the chance of a 32°F night stays under 10% each month. In spring, June still brings one in 14% of years.
Warmth for growing adds up to 2,338 growing degree days a year (base 50°F), more than at 82% of the 33 North Dakota stations. 30% of them (690) have built up by the end of June, and July adds the most, 638. Precipitation totals 16.8 inches a year, most in June (3.3") and least in December (0.2"); May to September bring 69% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 23 | 3 | 0.3 | 100% | 31 | 0 |
| Feb | 29 | 7 | 0.5 | 100% | 28 | 0 |
| Mar | 43 | 18 | 0.7 | 100% | 28 | 4 |
| Apr | 58 | 29 | 1.6 | 100% | 18 | 48 |
| May | 69 | 41 | 2.4 | 98% | 7 | 209 |
| Jun | 78 | 51 | 3.3 | 14% | 1 | 429 |
| Jul | 86 | 56 | 2.5 | 0% | 0 | 638 |
| Aug | 86 | 54 | 1.9 | 4% | <1 | 616 |
| Sep | 77 | 44 | 1.5 | 83% | 4 | 324 |
| Oct | 59 | 32 | 1.3 | 100% | 17 | 67 |
| Nov | 41 | 18 | 0.6 | 100% | 28 | 3 |
| Dec | 28 | 8 | 0.2 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Beulah 1 W, ND (1,785 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, Garrison, ND, 32 miles northeast of Beulah, has a last frost 7 days earlier (May 14), a first frost 6 days later (September 26), a season 12 days longer.
When it snows in Beulah, North Dakota
The first measurable snow (0.1 inch or more) in Beulah usually arrives around October 31, and the last of the season around April 4. Those are the middle dates across the winters of 1991–2020 at Beulah 1 W, ND, 2.7 miles away: half of years saw snow earlier, half later. Every one of those winters saw snow. The last 32°F night of spring typically comes 47 days after the last snow.
Planting calendar for 58523
| When | What to do |
|---|---|
| March 12 – March 26 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 26 – April 9 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 23 – May 7 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 21 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by June 28 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 6 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 20 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 58523 is 3 miles from Beulah 1 W, ND, which stands at 1,785 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station; its figures are presented in full for 58545 (Hazen). The 2023 USDA Plant Hardiness Zone Map lists ZIP 58523 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.