USDA Hardiness Zone 5a
Frost Dates for 57103 — Sioux Falls, South Dakota
NOAA 1991–2020 normals from Sioux Falls, SD (1,430 ft), 4 miles northwest.
Updated
In Sioux Falls, the last spring frost (32°F) is around May 1 in half of years and has passed by May 14 in nine years out of ten. The first fall frost comes around October 6, as early as September 23 one year in ten, leaving a typical freeze-free season of 157 days (NOAA, Sioux Falls, SD).
- Last spring frost
- May 1
- First fall frost
- October 6
- Growing season
- 157 days
- Hardiness zone
- 5a
50% probability
50% probability
freeze-free, 50%
-20 to -15°F (-28.9 to -26.1°C) coldest night
- First snow
- November 6
- Last snow
- April 13
- Winters with snow
- 100%
- Snow per year
- 45.3"
median, 1991–2020
median, 1991–2020
30 of 30 observed
NOAA normal
Frost risk by date in Sioux Falls
Half of springs at Sioux Falls, SD see their last 32°F night by May 1; only one in ten is past it by April 18, and one in ten still has one after May 14. Planting tender crops after May 6 leaves a 30% risk of a frost on them, after May 10 20%, and after May 14 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 6 in half of years, as early as September 23 one year in ten, and holds off past October 20 one year in ten. A hard freeze of 28°F follows 11 days later, around October 17; in spring the one-in-ten date for 28°F is May 5, 9 days before the 32°F one. The freeze-free season lasts 157 days in a typical year, longer than at 78% of the 49 South Dakota stations; it reaches 176 days one year in ten and falls short of 138 one year in ten. On average 162 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 10, and return around September 27. Severe cold of 16°F or below comes every winter, usually between November 11 and March 25.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 29 | May 2 | May 5 | May 7 | May 10 | May 12 | May 15 | May 18 | May 23 |
| 32°F | Apr 18 | Apr 23 | Apr 26 | Apr 29 | May 1 | May 3 | May 6 | May 10 | May 14 |
| 28°F | Apr 8 | Apr 12 | Apr 16 | Apr 19 | Apr 22 | Apr 25 | Apr 28 | May 1 | May 5 |
| 24°F | Mar 30 | Apr 3 | Apr 7 | Apr 10 | Apr 13 | Apr 16 | Apr 19 | Apr 22 | Apr 27 |
| 20°F | Mar 18 | Mar 23 | Mar 28 | Apr 1 | Apr 4 | Apr 7 | Apr 10 | Apr 13 | Apr 19 |
| 16°F | Mar 9 | Mar 13 | Mar 17 | Mar 21 | Mar 25 | Mar 29 | Apr 1 | Apr 5 | Apr 10 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 14 | Sep 19 | Sep 22 | Sep 25 | Sep 27 | Sep 30 | Oct 2 | Oct 5 | Oct 10 |
| 32°F | Sep 23 | Sep 27 | Sep 30 | Oct 3 | Oct 6 | Oct 9 | Oct 12 | Oct 15 | Oct 20 |
| 28°F | Oct 1 | Oct 6 | Oct 11 | Oct 14 | Oct 17 | Oct 20 | Oct 22 | Oct 25 | Oct 30 |
| 24°F | Oct 13 | Oct 19 | Oct 22 | Oct 24 | Oct 27 | Oct 29 | Nov 1 | Nov 4 | Nov 10 |
| 20°F | Oct 23 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 6 | Nov 9 | Nov 12 | Nov 17 |
| 16°F | Oct 30 | Nov 2 | Nov 6 | Nov 9 | Nov 11 | Nov 13 | Nov 17 | Nov 21 | Nov 25 |
Freeze probabilities 1991–2020 at Sioux Falls, 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 57103 →Compare Sioux Falls with another place →
Weather by month in Sioux Falls
July is the warmest month at Sioux Falls, SD, averaging 85°F by day and 63°F at night; January is the coldest at 27°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 52% of years.
Warmth for growing adds up to 2,989 growing degree days a year (base 50°F), more than at 84% of the 49 South Dakota stations. 34% of them (1,003) have built up by the end of June, and July adds the most, 755. Precipitation totals 27.8 inches a year, most in June (4.2") and least in January (0.6"); May to September bring 63% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 27 | 9 | 0.6 | 100% | 31 | 0 |
| Feb | 32 | 13 | 0.8 | 100% | 27 | 1 |
| Mar | 45 | 24 | 1.6 | 100% | 25 | 17 |
| Apr | 59 | 36 | 3.0 | 100% | 13 | 85 |
| May | 71 | 48 | 3.9 | 52% | 1 | 305 |
| Jun | 81 | 59 | 4.2 | 0% | 0 | 596 |
| Jul | 85 | 63 | 3.3 | 0% | 0 | 755 |
| Aug | 83 | 61 | 3.3 | 0% | 0 | 680 |
| Sep | 76 | 52 | 2.7 | 30% | 1 | 419 |
| Oct | 61 | 38 | 2.4 | 99% | 10 | 120 |
| Nov | 45 | 25 | 1.2 | 100% | 24 | 12 |
| Dec | 32 | 13 | 0.8 | 100% | 30 | 0 |
Monthly normals 1991–2020 at Sioux Falls, SD (1,430 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, Sioux Falls WFO Airport, SD, 4 miles northwest of Sioux Falls, has a last frost 5 days earlier (April 26), a first frost 7 days later (October 13), a season 12 days longer.
When it snows in Sioux Falls, South Dakota
The first measurable snow (0.1 inch or more) in Sioux Falls usually arrives around November 6, and the last of the season around April 13. Those are the middle dates across the winters of 1991–2020 at Sioux Falls, SD, 3.9 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 18 days after the last snow.
Planting calendar for 57103
| When | What to do |
|---|---|
| February 20 – March 6 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 6 – March 20 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 3 – April 17 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 1 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 14 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 22 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 6 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 57103 is 4 miles from Sioux Falls, SD, which stands at 1,430 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. 3 other ZIP codes share the station. The 2023 USDA Plant Hardiness Zone Map lists ZIP 57103 in zone 5a, the band where the coldest night of the year averaged -20 to -15°F (-28.9 to -26.1°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.