USDA Hardiness Zone 4b
Frost Dates for 57501 — Pierre, South Dakota
NOAA 1991–2020 normals from Pierre Regional Airport, SD (1,742 ft), 3 miles south.
Updated
In Pierre, the last spring frost (32°F) is around May 6 in half of years and has passed by May 21 in nine years out of ten. The first fall frost comes around October 3, as early as September 20 one year in ten, leaving a typical freeze-free season of 148 days (NOAA, Pierre Regional Airport, SD).
- Last spring frost
- May 6
- First fall frost
- October 3
- Growing season
- 148 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
- November 8
- Last snow
- April 13
- Winters with snow
- 100%
- Snow per year
- 37.2"
median, 1991–2020
median, 1991–2020
20 of 20 observed
NOAA normal
Frost risk by date in Pierre
Half of springs at Pierre Regional Airport, SD see their last 32°F night by May 6; only one in ten is past it by April 24, and one in ten still has one after May 21. Planting tender crops after May 12 leaves a 30% risk of a frost on them, after May 16 20%, and after May 21 10%. The 15 days between the even-odds date and the one-in-ten date is wider than at 84% of the 49 South Dakota stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 3 in half of years, as early as September 20 one year in ten, and holds off past October 17 one year in ten. A hard freeze of 28°F follows 9 days later, around October 12; in spring the one-in-ten date for 28°F is May 10, 11 days before the 32°F one. The freeze-free season lasts 148 days in a typical year, shorter than at 51% of the 49 South Dakota stations; it reaches 167 days one year in ten and falls short of 130 one year in ten. On average 164 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 16, and return around September 25. Severe cold of 16°F or below comes every winter, usually between November 9 and March 29.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 3 | May 7 | May 11 | May 13 | May 16 | May 19 | May 22 | May 25 | May 30 |
| 32°F | Apr 24 | Apr 29 | May 2 | May 4 | May 6 | May 9 | May 12 | May 16 | May 21 |
| 28°F | Apr 12 | Apr 17 | Apr 20 | Apr 23 | Apr 26 | Apr 29 | May 1 | May 5 | May 10 |
| 24°F | Apr 1 | Apr 6 | Apr 10 | Apr 14 | Apr 17 | Apr 19 | Apr 22 | Apr 26 | May 1 |
| 20°F | Mar 20 | Mar 28 | Apr 1 | Apr 3 | Apr 6 | Apr 9 | Apr 13 | Apr 17 | Apr 22 |
| 16°F | Mar 10 | Mar 15 | Mar 20 | Mar 26 | Mar 29 | Apr 1 | Apr 4 | Apr 8 | Apr 13 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 13 | Sep 17 | Sep 20 | Sep 23 | Sep 25 | Sep 28 | Oct 1 | Oct 3 | Oct 8 |
| 32°F | Sep 20 | Sep 24 | Sep 28 | Sep 30 | Oct 3 | Oct 6 | Oct 9 | Oct 13 | Oct 17 |
| 28°F | Sep 27 | Oct 1 | Oct 5 | Oct 9 | Oct 12 | Oct 15 | Oct 19 | Oct 22 | Oct 27 |
| 24°F | Oct 5 | Oct 12 | Oct 16 | Oct 19 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 5 |
| 20°F | Oct 16 | Oct 22 | Oct 27 | Oct 29 | Nov 1 | Nov 4 | Nov 6 | Nov 10 | Nov 14 |
| 16°F | Oct 27 | Nov 1 | Nov 3 | Nov 6 | Nov 9 | Nov 12 | Nov 15 | Nov 19 | Nov 24 |
Freeze probabilities 1991–2020 at Pierre Regional Airport, 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 57501 →Compare Pierre with another place →
Weather by month in Pierre
July is the warmest month at Pierre Regional Airport, SD, averaging 88°F by day and 62°F at night; January is the coldest at 29°F and 9°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 73% of years.
Warmth for growing adds up to 2,889 growing degree days a year (base 50°F), more than at 76% of the 49 South Dakota stations. 30% of them (873) have built up by the end of June, and July adds the most, 773. Precipitation totals 20.3 inches a year, most in June (3.7") and least in January (0.5"); May to September bring 65% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 29 | 9 | 0.5 | 100% | 31 | 0 |
| Feb | 34 | 13 | 0.7 | 100% | 27 | 1 |
| Mar | 46 | 23 | 1.0 | 100% | 25 | 13 |
| Apr | 59 | 33 | 1.9 | 100% | 13 | 67 |
| May | 70 | 45 | 3.3 | 73% | 2 | 257 |
| Jun | 80 | 56 | 3.7 | 1% | 0 | 535 |
| Jul | 88 | 62 | 2.4 | 0% | 0 | 773 |
| Aug | 87 | 59 | 2.0 | 0% | 0 | 713 |
| Sep | 78 | 50 | 1.7 | 40% | 1 | 416 |
| Oct | 61 | 36 | 1.7 | 100% | 10 | 106 |
| Nov | 45 | 23 | 0.8 | 100% | 25 | 8 |
| Dec | 32 | 13 | 0.6 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Pierre Regional Airport, SD (1,742 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, Oahe Dam, SD, 6 miles west of Pierre, has the same 50% last-frost date, a first frost 2 days later (October 5), a season 4 days longer.
When it snows in Pierre, South Dakota
The first measurable snow (0.1 inch or more) in Pierre usually arrives around November 8, and the last of the season around April 13. Those are the middle dates across the winters of 1991–2020 at Pierre Regional Airport, SD, 3.1 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 23 days after the last snow.
Planting calendar for 57501
| When | What to do |
|---|---|
| February 25 – March 11 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 11 – March 25 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 8 – April 22 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 6 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 11 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 19 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 3 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 57501 is 3 miles from Pierre Regional Airport, SD, which stands at 1,742 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 57501 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.