USDA Hardiness Zone 4a
Frost Dates for 58257 — Mayville, North Dakota
NOAA 1991–2020 normals from Mayville, ND (983 ft), 3 miles west.
Updated
In Mayville, the last spring frost (32°F) is around May 13 in half of years and has passed by May 25 in nine years out of ten. The first fall frost comes around September 27, as early as September 14 one year in ten, leaving a typical freeze-free season of 136 days (NOAA, Mayville, ND).
- Last spring frost
- May 13
- First fall frost
- September 27
- Growing season
- 136 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 5
- Last snow
- April 1
- Winters with snow
- 100%
- Snow per year
- 34.7"
median, 1991–2020
median, 1991–2020
18 of 18 observed
NOAA normal
Frost risk by date in Mayville
Half of springs at Mayville, ND see their last 32°F night by May 13; only one in ten is past it by April 30, 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 12 days between the even-odds date and the one-in-ten date is narrower than at 79% of the 33 North Dakota stations behind this site's ZIP pages.
In fall the first 32°F night comes by September 27 in half of years, as early as September 14 one year in ten, and holds off past October 9 one year in ten. A hard freeze of 28°F follows 9 days later, around October 6; in spring the one-in-ten date for 28°F is May 17, 8 days before the 32°F one. The freeze-free season lasts 136 days in a typical year, shorter than at 52% of the 33 North Dakota stations; it reaches 154 days one year in ten and falls short of 119 one year in ten. On average 189 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 23, and return around September 17. Severe cold of 16°F or below comes every winter, usually between November 3 and April 6.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 11 | May 15 | May 18 | May 21 | May 23 | May 25 | May 27 | May 30 | Jun 2 |
| 32°F | Apr 30 | May 4 | May 8 | May 11 | May 13 | May 15 | May 18 | May 21 | May 25 |
| 28°F | Apr 20 | Apr 26 | Apr 29 | May 1 | May 4 | May 7 | May 10 | May 13 | May 17 |
| 24°F | Apr 9 | Apr 14 | Apr 18 | Apr 21 | Apr 25 | Apr 27 | Apr 30 | May 4 | May 8 |
| 20°F | Apr 2 | Apr 5 | Apr 8 | Apr 11 | Apr 13 | Apr 16 | Apr 19 | Apr 24 | Apr 29 |
| 16°F | Mar 23 | Mar 31 | Apr 2 | Apr 4 | Apr 6 | Apr 9 | Apr 12 | Apr 15 | Apr 21 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 4 | Sep 9 | Sep 13 | Sep 15 | Sep 17 | Sep 20 | Sep 22 | Sep 24 | Sep 28 |
| 32°F | Sep 14 | Sep 19 | Sep 22 | Sep 25 | Sep 27 | Sep 29 | Oct 1 | Oct 4 | Oct 9 |
| 28°F | Sep 24 | Sep 28 | Oct 1 | Oct 3 | Oct 6 | Oct 8 | Oct 11 | Oct 15 | Oct 19 |
| 24°F | Oct 1 | Oct 6 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 25 | Oct 29 |
| 20°F | Oct 11 | Oct 16 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 9 |
| 16°F | Oct 21 | Oct 26 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 17 |
Freeze probabilities 1991–2020 at Mayville, 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 58257 →Compare Mayville with another place →
Weather by month in Mayville
July is the warmest month at Mayville, ND, averaging 80°F by day and 57°F at night; January is the coldest at 16°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 89% of years.
Warmth for growing adds up to 2,010 growing degree days a year (base 50°F), fewer than at 70% of the 33 North Dakota stations. 32% of them (644) have built up by the end of June, and July adds the most, 569. Precipitation totals 24.0 inches a year, most in June (4.1") and least in January (0.5"); May to September bring 70% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 16 | -4 | 0.5 | 100% | 31 | 0 |
| Feb | 21 | 0 | 0.5 | 100% | 28 | 0 |
| Mar | 33 | 13 | 1.0 | 100% | 29 | 1 |
| Apr | 51 | 28 | 1.5 | 100% | 19 | 20 |
| May | 67 | 41 | 3.3 | 89% | 5 | 180 |
| Jun | 76 | 53 | 4.1 | 0% | 0 | 443 |
| Jul | 80 | 57 | 3.9 | 0% | 0 | 569 |
| Aug | 79 | 54 | 2.7 | 0% | 0 | 513 |
| Sep | 70 | 44 | 2.7 | 67% | 2 | 240 |
| Oct | 54 | 32 | 2.1 | 100% | 16 | 44 |
| Nov | 36 | 17 | 0.8 | 100% | 28 | 0 |
| Dec | 22 | 5 | 0.9 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Mayville, ND (983 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, Hillsboro 3 N, ND, 11 miles east of Mayville, has a last frost 11 days earlier (May 2), a first frost 12 days later (October 9), a season 22 days longer.
When it snows in Mayville, North Dakota
The first measurable snow (0.1 inch or more) in Mayville usually arrives around November 5, and the last of the season around April 1. Those are the middle dates across the winters of 1991–2020 at Colgate, ND, 24.1 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 42 days after the last snow.
Planting calendar for 58257
| When | What to do |
|---|---|
| March 4 – March 18 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 18 – April 1 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 15 – April 29 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 13 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 5 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 13 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 27 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 58257 is 3 miles from Mayville, ND, which stands at 983 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 58257 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.