USDA Hardiness Zone 5a
Frost Dates for 57555 — Mission, South Dakota
NOAA 1991–2020 normals from Mission, SD (2,587 ft), 5 miles north.
Updated
In Mission, the last spring frost (32°F) is around May 9 in half of years and has passed by May 21 in nine years out of ten. The first fall frost comes around October 1, as early as September 19 one year in ten, leaving a typical freeze-free season of 146 days (NOAA, Mission, SD).
- Last spring frost
- May 9
- First fall frost
- October 1
- Growing season
- 146 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 5
- Last snow
- April 12
- Winters with snow
- 100%
- Snow per year
- 41.5"
median, 1991–2020
median, 1991–2020
22 of 22 observed
NOAA normal
Frost risk by date in Mission
Half of springs at Mission, SD see their last 32°F night by May 9; only one in ten is past it by April 28, 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 12 days between the even-odds date and the one-in-ten date is narrower than at 90% of the 49 South Dakota stations behind this site's ZIP pages.
In fall the first 32°F night comes by October 1 in half of years, as early as September 19 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 12; in spring the one-in-ten date for 28°F is May 13, 8 days before the 32°F one. The freeze-free season lasts 146 days in a typical year, shorter than at 63% of the 49 South Dakota stations; it reaches 163 days one year in ten and falls short of 126 one year in ten. On average 165 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 19, and return around September 24. Severe cold of 16°F or below comes every winter, usually between November 7 and April 1.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | May 6 | May 11 | May 13 | May 16 | May 19 | May 22 | May 25 | May 29 | Jun 3 |
| 32°F | Apr 28 | May 1 | May 4 | May 6 | May 9 | May 11 | May 14 | May 17 | May 21 |
| 28°F | Apr 17 | Apr 22 | Apr 25 | Apr 28 | Apr 30 | May 2 | May 5 | May 9 | May 13 |
| 24°F | Apr 7 | Apr 10 | Apr 14 | Apr 18 | Apr 20 | Apr 23 | Apr 26 | Apr 29 | May 3 |
| 20°F | Mar 25 | Apr 1 | Apr 4 | Apr 7 | Apr 10 | Apr 13 | Apr 16 | Apr 20 | Apr 25 |
| 16°F | Mar 13 | Mar 20 | Mar 25 | Mar 29 | Apr 1 | Apr 4 | Apr 7 | Apr 11 | Apr 17 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 11 | Sep 16 | Sep 19 | Sep 21 | Sep 24 | Sep 27 | Sep 29 | Oct 1 | Oct 6 |
| 32°F | Sep 19 | Sep 23 | Sep 27 | Sep 30 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 15 |
| 28°F | Sep 28 | Oct 2 | Oct 5 | Oct 9 | Oct 12 | Oct 15 | Oct 18 | Oct 20 | Oct 25 |
| 24°F | Oct 6 | Oct 12 | Oct 15 | Oct 18 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 3 |
| 20°F | Oct 16 | Oct 21 | Oct 24 | Oct 27 | Oct 30 | Nov 2 | Nov 5 | Nov 9 | Nov 15 |
| 16°F | Oct 24 | Oct 29 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 14 | Nov 18 | Nov 23 |
Freeze probabilities 1991–2020 at Mission, 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 57555 →Compare Mission with another place →
Weather by month in Mission
July is the warmest month at Mission, SD, averaging 87°F by day and 61°F at night; January is the coldest at 34°F and 12°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 82% of years.
Warmth for growing adds up to 2,789 growing degree days a year (base 50°F), more than at 59% of the 49 South Dakota stations. 30% of them (833) have built up by the end of June, and July adds the most, 748. Precipitation totals 21.1 inches a year, most in June (3.7") and least in January (0.5"); May to September bring 63% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 34 | 12 | 0.5 | 100% | 30 | 1 |
| Feb | 38 | 14 | 0.7 | 100% | 27 | 2 |
| Mar | 48 | 23 | 1.1 | 100% | 25 | 19 |
| Apr | 57 | 32 | 2.5 | 100% | 14 | 61 |
| May | 68 | 44 | 3.4 | 82% | 2 | 237 |
| Jun | 79 | 55 | 3.7 | 0% | 0 | 515 |
| Jul | 87 | 61 | 2.6 | 0% | 0 | 748 |
| Aug | 86 | 59 | 1.8 | 0% | 0 | 687 |
| Sep | 77 | 48 | 1.8 | 43% | 1 | 395 |
| Oct | 62 | 35 | 1.7 | 99% | 11 | 107 |
| Nov | 48 | 23 | 0.7 | 100% | 25 | 18 |
| Dec | 37 | 14 | 0.6 | 100% | 30 | 1 |
Monthly normals 1991–2020 at Mission, SD (2,587 ft), NOAA NCEI. "32°F night": chance of at least one in the month. GDD: growing degree days, base 50°F.
When it snows in Mission, South Dakota
The first measurable snow (0.1 inch or more) in Mission usually arrives around November 5, and the last of the season around April 12. Those are the middle dates across the winters of 1991–2020 at Mission, SD, 5 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 27 days after the last snow.
Planting calendar for 57555
| When | What to do |
|---|---|
| February 28 – March 14 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 14 – March 28 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 11 – April 25 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 9 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 9 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 17 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 1 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 57555 is 5 miles from Mission, SD, which stands at 2,587 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 57555 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.