USDA Hardiness Zone 4a
Frost Dates for 58220 — Cavalier, North Dakota
NOAA 1991–2020 normals from Cavalier 7NW, ND (899 ft), 5 miles north.
Updated
In Cavalier, the last spring frost (32°F) is around May 12 in half of years and has passed by May 27 in nine years out of ten. The first fall frost comes around September 30, as early as September 17 one year in ten, leaving a typical freeze-free season of 139 days (NOAA, Cavalier 7NW, ND).
- Last spring frost
- May 12
- First fall frost
- September 30
- Growing season
- 139 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 10
- Winters with snow
- 100%
- Snow per year
- 39.1"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Cavalier
Half of springs at Cavalier 7NW, ND see their last 32°F night by May 12; only one in ten is past it by April 29, and one in ten still has one after May 27. Planting tender crops after May 17 leaves a 30% risk of a frost on them, after May 21 20%, and after May 27 10%. The 15 days between the even-odds date and the one-in-ten date is the widest of the 33 North Dakota stations behind this site's ZIP pages.
In fall the first 32°F night comes by September 30 in half of years, as early as September 17 one year in ten, and holds off past October 13 one year in ten. A hard freeze of 28°F follows 10 days later, around October 10; in spring the one-in-ten date for 28°F is May 17, 10 days before the 32°F one. The freeze-free season lasts 139 days in a typical year, longer than at 58% of the 33 North Dakota stations; it reaches 157 days one year in ten and falls short of 121 one year in ten. On average 192 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 22, and return around September 21. Severe cold of 16°F or below comes every winter, usually between November 5 and April 5.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 9 | May 13 | May 16 | May 19 | May 22 | May 25 | May 28 | May 31 | Jun 3 |
| 32°F | Apr 29 | May 4 | May 6 | May 9 | May 12 | May 15 | May 17 | May 21 | May 27 |
| 28°F | Apr 17 | Apr 22 | Apr 27 | Apr 30 | May 2 | May 5 | May 8 | May 12 | May 17 |
| 24°F | Apr 6 | Apr 12 | Apr 16 | Apr 19 | Apr 22 | Apr 26 | Apr 29 | May 1 | May 6 |
| 20°F | Mar 30 | Apr 3 | Apr 6 | Apr 9 | Apr 12 | Apr 15 | Apr 18 | Apr 21 | Apr 26 |
| 16°F | Mar 21 | Mar 28 | Apr 1 | Apr 3 | Apr 5 | Apr 7 | Apr 10 | Apr 14 | Apr 19 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 8 | Sep 13 | Sep 16 | Sep 18 | Sep 21 | Sep 23 | Sep 26 | Sep 29 | Oct 3 |
| 32°F | Sep 17 | Sep 21 | Sep 25 | Sep 28 | Sep 30 | Oct 2 | Oct 5 | Oct 9 | Oct 13 |
| 28°F | Sep 27 | Oct 1 | Oct 3 | Oct 6 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 23 |
| 24°F | Oct 4 | Oct 11 | Oct 14 | Oct 18 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 2 |
| 20°F | Oct 15 | Oct 20 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 11 |
| 16°F | Oct 24 | Oct 28 | Nov 1 | Nov 2 | Nov 5 | Nov 7 | Nov 10 | Nov 14 | Nov 19 |
Freeze probabilities 1991–2020 at Cavalier 7NW, 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 58220 →Compare Cavalier with another place →
Weather by month in Cavalier
July is the warmest month at Cavalier 7NW, ND, averaging 78°F by day and 57°F at night; January is the coldest at 13°F and -4°F. A freezing night is all but certain in every month from October to April (a 90% chance or more). From June to August the chance of a 32°F night stays under 10% each month. In spring, May still brings one in 86% of years.
Warmth for growing adds up to 1,853 growing degree days a year (base 50°F), fewer than at 91% of the 33 North Dakota stations. 31% of them (583) have built up by the end of June, and July adds the most, 529. Precipitation totals 20.0 inches a year, most in June (3.8") and least in January (0.3"); May to September bring 74% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 13 | -4 | 0.3 | 100% | 31 | 0 |
| Feb | 18 | -1 | 0.3 | 100% | 28 | 0 |
| Mar | 31 | 13 | 0.7 | 100% | 30 | 1 |
| Apr | 49 | 29 | 1.1 | 100% | 21 | 20 |
| May | 65 | 41 | 2.9 | 86% | 6 | 165 |
| Jun | 74 | 53 | 3.8 | 4% | 0 | 397 |
| Jul | 78 | 57 | 3.4 | 0% | 0 | 529 |
| Aug | 77 | 54 | 2.3 | 0% | 0 | 479 |
| Sep | 68 | 45 | 2.3 | 51% | 2 | 225 |
| Oct | 52 | 32 | 1.7 | 100% | 16 | 37 |
| Nov | 34 | 17 | 0.7 | 100% | 28 | 1 |
| Dec | 20 | 3 | 0.5 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Cavalier 7NW, ND (899 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, Grafton, ND, 29 miles southeast of Cavalier, has a last frost 8 days earlier (May 4), a first frost 7 days later (October 7), a season 17 days longer.
When it snows in Cavalier, North Dakota
The first measurable snow (0.1 inch or more) in Cavalier usually arrives around October 31, and the last of the season around April 10. Those are the middle dates across the winters of 1991–2020 at Cavalier 7NW, ND, 4.5 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 32 days after the last snow.
Planting calendar for 58220
| 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 8 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 16 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 30 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 58220 is 5 miles from Cavalier 7NW, ND, which stands at 899 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 58220 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.