USDA Hardiness Zone 4a
Frost Dates for 57401 — Aberdeen, South Dakota
NOAA 1991–2020 normals from Aberdeen 3 E, SD (1,301 ft), 4 miles east.
Updated
In Aberdeen, the last spring frost (32°F) is around May 8 in half of years and has passed by May 21 in nine years out of ten. The first fall frost comes around September 29, as early as September 17 one year in ten, leaving a typical freeze-free season of 144 days (NOAA, Aberdeen 3 E, SD).
- Last spring frost
- May 8
- First fall frost
- September 29
- Growing season
- 144 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 13
- Winters with snow
- 100%
- Snow per year
- 42.7"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Aberdeen
Half of springs at Aberdeen 3 E, SD see their last 32°F night by May 8; only one in ten is past it by April 25, and one in ten still has one after May 21. Planting tender crops after May 14 leaves a 30% risk of a frost on them, after May 17 20%, and after May 21 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 September 29 in half of years, as early as September 17 one year in ten, and holds off past October 11 one year in ten. A hard freeze of 28°F follows 8 days later, around October 7; in spring the one-in-ten date for 28°F is May 12, 9 days before the 32°F one. The freeze-free season lasts 144 days in a typical year, shorter than at 73% of the 49 South Dakota stations; it reaches 162 days one year in ten and falls short of 126 one year in ten. On average 180 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 18, and return around September 21. Severe cold of 16°F or below comes every winter, usually between November 3 and April 2.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 5 | May 9 | May 12 | May 15 | May 18 | May 21 | May 24 | May 27 | May 31 |
| 32°F | Apr 25 | Apr 30 | May 3 | May 6 | May 8 | May 11 | May 14 | May 17 | May 21 |
| 28°F | Apr 13 | Apr 18 | Apr 22 | Apr 26 | Apr 29 | May 2 | May 4 | May 7 | May 12 |
| 24°F | Apr 4 | Apr 8 | Apr 12 | Apr 15 | Apr 18 | Apr 21 | Apr 25 | Apr 29 | May 3 |
| 20°F | Mar 26 | Apr 1 | Apr 4 | Apr 6 | Apr 9 | Apr 12 | Apr 15 | Apr 19 | Apr 24 |
| 16°F | Mar 16 | Mar 22 | Mar 27 | Mar 30 | Apr 2 | Apr 4 | Apr 8 | Apr 10 | Apr 16 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 8 | Sep 12 | Sep 16 | Sep 18 | Sep 21 | Sep 23 | Sep 25 | Sep 27 | Sep 30 |
| 32°F | Sep 17 | Sep 21 | Sep 24 | Sep 27 | Sep 29 | Oct 1 | Oct 3 | Oct 7 | Oct 11 |
| 28°F | Sep 25 | Sep 28 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 20 |
| 24°F | Oct 3 | Oct 7 | Oct 11 | Oct 14 | Oct 16 | Oct 19 | Oct 22 | Oct 25 | Oct 29 |
| 20°F | Oct 10 | Oct 16 | Oct 20 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 3 | Nov 8 |
| 16°F | Oct 21 | Oct 26 | Oct 30 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 13 | Nov 17 |
Freeze probabilities 1991–2020 at Aberdeen 3 E, 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 57401 →Compare Aberdeen with another place →
Compared with the next station
The nearest other station, Ipswich, SD, 26 miles west of Aberdeen and 246 feet higher, has the same 50% last-frost date, the same first-frost date, a season 1 day shorter.
When it snows in Aberdeen, South Dakota
The first measurable snow (0.1 inch or more) in Aberdeen usually arrives around October 31, and the last of the season around April 13. Those are the middle dates across the winters of 1991–2020 at Aberdeen, SD, 4.1 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 25 days after the last snow.
Planting calendar for 57401
| When | What to do |
|---|---|
| February 27 – March 13 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 13 – March 27 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 10 – April 24 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 8 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 7 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 15 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 29 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 57401 is 4 miles from Aberdeen 3 E, SD, which stands at 1,301 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 57401 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 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.