USDA Hardiness Zone 4b
Frost Dates for 57252 — Milbank, South Dakota
NOAA 1991–2020 normals from Milbank, SD (1,142 ft), 1 miles northwest.
Updated
In Milbank, the last spring frost (32°F) is around May 5 in half of years and has passed by May 18 in nine years out of ten. The first fall frost comes around October 2, as early as September 20 one year in ten, leaving a typical freeze-free season of 150 days (NOAA, Milbank, SD).
- Last spring frost
- May 5
- First fall frost
- October 2
- Growing season
- 150 days
- Hardiness zone
- 4b
50% probability
50% probability
freeze-free, 50%
-25 to -20°F (-31.7 to -28.9°C) coldest night
- First snow
- December 1
- Last snow
- March 26
- Winters with snow
- 100%
- Snow per year
- 32.2"
median, 1991–2020
median, 1991–2020
25 of 25 observed
NOAA normal
Frost risk by date in Milbank
Half of springs at Milbank, SD see their last 32°F night by May 5; only one in ten is past it by April 22, and one in ten still has one after May 18. Planting tender crops after May 11 leaves a 30% risk of a frost on them, after May 14 20%, and after May 18 10%. The 13 days between the even-odds date and the one-in-ten date is narrower than at 43% of the 49 South Dakota stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 2 in half of years, as early as September 20 one year in ten, and holds off past October 15 one year in ten. A hard freeze of 28°F follows 11 days later, around October 13; in spring the one-in-ten date for 28°F is May 9, 9 days before the 32°F one. The freeze-free season lasts 150 days in a typical year, longer than at 53% of the 49 South Dakota stations; it reaches 167 days one year in ten and falls short of 132 one year in ten. On average 171 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 14, and return around September 24. Severe cold of 16°F or below comes every winter, usually between November 10 and March 31.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 3 | May 7 | May 10 | May 12 | May 14 | May 17 | May 19 | May 23 | May 27 |
| 32°F | Apr 22 | Apr 28 | May 1 | May 3 | May 5 | May 8 | May 11 | May 14 | May 18 |
| 28°F | Apr 10 | Apr 16 | Apr 19 | Apr 22 | Apr 25 | Apr 29 | May 1 | May 4 | May 9 |
| 24°F | Apr 2 | Apr 6 | Apr 8 | Apr 11 | Apr 15 | Apr 18 | Apr 21 | Apr 25 | Apr 30 |
| 20°F | Mar 23 | Mar 30 | Apr 2 | Apr 4 | Apr 6 | Apr 8 | Apr 11 | Apr 16 | Apr 21 |
| 16°F | Mar 14 | Mar 21 | Mar 25 | Mar 29 | Mar 31 | Apr 2 | Apr 4 | Apr 8 | Apr 13 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 12 | Sep 16 | Sep 19 | Sep 22 | Sep 24 | Sep 26 | Sep 29 | Oct 1 | Oct 5 |
| 32°F | Sep 20 | Sep 25 | Sep 28 | Sep 30 | Oct 2 | Oct 5 | Oct 8 | Oct 10 | Oct 15 |
| 28°F | Sep 29 | Oct 3 | Oct 6 | Oct 9 | Oct 13 | Oct 16 | Oct 19 | Oct 22 | Oct 26 |
| 24°F | Oct 8 | Oct 13 | Oct 18 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 2 | Nov 8 |
| 20°F | Oct 19 | Oct 24 | Oct 28 | Oct 31 | Nov 2 | Nov 5 | Nov 8 | Nov 11 | Nov 16 |
| 16°F | Oct 28 | Nov 1 | Nov 5 | Nov 8 | Nov 10 | Nov 13 | Nov 16 | Nov 19 | Nov 25 |
Freeze probabilities 1991–2020 at Milbank, 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 57252 →Compare Milbank with another place →
Weather by month in Milbank
July is the warmest month at Milbank, SD, averaging 81°F by day and 60°F at night; January is the coldest at 21°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 70% of years.
Warmth for growing adds up to 2,372 growing degree days a year (base 50°F), fewer than at 86% of the 49 South Dakota stations. 33% of them (775) have built up by the end of June, and July adds the most, 638.
| Month | High °F | Low °F | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|
| Jan | 21 | 4 | 100% | 31 | 0 |
| Feb | 26 | 7 | 100% | 28 | 0 |
| Mar | 38 | 19 | 100% | 28 | 7 |
| Apr | 54 | 32 | 100% | 16 | 44 |
| May | 67 | 45 | 70% | 2 | 228 |
| Jun | 77 | 56 | 0% | 0 | 497 |
| Jul | 81 | 60 | 0% | 0 | 638 |
| Aug | 79 | 57 | 0% | 0 | 564 |
| Sep | 72 | 48 | 40% | 1 | 311 |
| Oct | 58 | 35 | 100% | 11 | 80 |
| Nov | 41 | 22 | 100% | 24 | 5 |
| Dec | 27 | 10 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Milbank, SD (1,142 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, Madison Wwtp, MN, 26 miles southeast of Milbank, has a last frost 2 days earlier (May 3), the same first-frost date, a season 1 day longer.
When it snows in Milbank, South Dakota
The first measurable snow (0.1 inch or more) in Milbank usually arrives around December 1, and the last of the season around March 26. Those are the middle dates across the winters of 1991–2020 at Big Stone City 2 NW, SD, 7.9 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 40 days after the last snow.
Planting calendar for 57252
| When | What to do |
|---|---|
| February 24 – March 10 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 10 – March 24 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 7 – April 21 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 5 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 10 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 18 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 2 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 57252 is 1 mile from Milbank, SD, which stands at 1,142 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 1 other ZIP code shares the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 57252 in zone 4b, the band where the coldest night of the year averaged -25 to -20°F (-31.7 to -28.9°C) over 1991–2020; a zone describes winter lows, not frost dates.
Frost dates across South 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.