USDA Hardiness Zone 5a
Frost Dates for 57325 — Chamberlain, South Dakota
NOAA 1991–2020 normals from Chamberlain Municipal Airport, SD (1,703 ft), 1 miles southwest.
Updated
In Chamberlain, 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 7, as early as September 23 one year in ten, leaving a typical freeze-free season of 158 days (NOAA, Chamberlain Municipal Airport, SD).
- Last spring frost
- May 1
- First fall frost
- October 7
- Growing season
- 158 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 7
- Last snow
- April 14
- Winters with snow
- 100%
- Snow per year
- 43.3"
median, 1991–2020
median, 1991–2020
28 of 28 observed
NOAA normal
Frost risk by date in Chamberlain
Half of springs at Chamberlain Municipal Airport, 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 9 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 7 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 9 days later, around October 16; in spring the one-in-ten date for 28°F is May 4, 10 days before the 32°F one. The freeze-free season lasts 158 days in a typical year, longer than at 82% of the 49 South Dakota stations; it reaches 176 days one year in ten and falls short of 139 one year in ten. On average 156 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 28. Severe cold of 16°F or below comes every winter, usually between November 13 and March 23.
| Low | 90% | 80% | 70% | 60% | 50% | 40% | 30% | 20% | 10% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Apr 30 | May 2 | May 5 | May 7 | May 10 | May 13 | May 16 | May 19 | May 24 |
| 32°F | Apr 18 | Apr 23 | Apr 27 | Apr 29 | May 1 | May 3 | May 6 | May 9 | May 14 |
| 28°F | Apr 7 | Apr 11 | Apr 15 | Apr 17 | Apr 21 | Apr 24 | Apr 27 | Apr 30 | May 4 |
| 24°F | Mar 28 | Apr 2 | Apr 4 | Apr 7 | Apr 10 | Apr 13 | Apr 17 | Apr 20 | Apr 25 |
| 20°F | Mar 14 | Mar 22 | Mar 27 | Mar 31 | Apr 2 | Apr 4 | Apr 7 | Apr 11 | Apr 17 |
| 16°F | Mar 6 | Mar 12 | Mar 15 | Mar 19 | Mar 23 | Mar 27 | Mar 31 | Apr 3 | Apr 9 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 17 | Sep 21 | Sep 24 | Sep 26 | Sep 28 | Oct 1 | Oct 3 | Oct 7 | Oct 12 |
| 32°F | Sep 23 | Sep 29 | Oct 1 | Oct 4 | Oct 7 | Oct 10 | Oct 13 | Oct 16 | Oct 20 |
| 28°F | Oct 1 | Oct 6 | Oct 10 | Oct 14 | Oct 16 | Oct 20 | Oct 22 | Oct 25 | Oct 30 |
| 24°F | Oct 11 | Oct 17 | Oct 21 | Oct 23 | Oct 26 | Oct 29 | Nov 1 | Nov 4 | Nov 9 |
| 20°F | Oct 21 | Oct 27 | Oct 30 | Nov 1 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 18 |
| 16°F | Oct 31 | Nov 4 | Nov 7 | Nov 10 | Nov 13 | Nov 15 | Nov 18 | Nov 22 | Nov 27 |
Freeze probabilities 1991–2020 at Chamberlain Municipal 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 57325 →Compare Chamberlain with another place →
Weather by month in Chamberlain
July is the warmest month at Chamberlain Municipal Airport, SD, averaging 88°F by day and 63°F at night; January is the coldest at 31°F and 11°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 53% of years.
Warmth for growing adds up to 3,032 growing degree days a year (base 50°F), more than at 86% of the 49 South Dakota stations. 32% of them (955) have built up by the end of June, and July adds the most, 782. Precipitation totals 20.4 inches a year, most in June (3.6") and least in January (0.4"); May to September bring 66% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 31 | 11 | 0.4 | 100% | 30 | 0 |
| Feb | 35 | 14 | 0.6 | 100% | 27 | 1 |
| Mar | 47 | 25 | 1.1 | 100% | 24 | 23 |
| Apr | 59 | 35 | 2.3 | 100% | 10 | 79 |
| May | 70 | 47 | 3.2 | 53% | 2 | 279 |
| Jun | 81 | 58 | 3.6 | 0% | 0 | 573 |
| Jul | 88 | 63 | 2.2 | 0% | 0 | 782 |
| Aug | 86 | 61 | 2.3 | 0% | 0 | 727 |
| Sep | 77 | 51 | 2.1 | 27% | <1 | 436 |
| Oct | 62 | 38 | 1.6 | 99% | 9 | 121 |
| Nov | 46 | 25 | 0.5 | 100% | 23 | 10 |
| Dec | 34 | 15 | 0.5 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Chamberlain Municipal Airport, SD (1,703 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, Academy 2NE, SD, 23 miles southeast of Chamberlain, has a last frost 1 day earlier (April 30), a first frost 1 day later (October 8), a season 1 day longer.
When it snows in Chamberlain, South Dakota
The first measurable snow (0.1 inch or more) in Chamberlain usually arrives around November 7, and the last of the season around April 14. Those are the middle dates across the winters of 1991–2020 at Chamberlain 5 S, SD, 3.2 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 17 days after the last snow.
Planting calendar for 57325
| 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 15 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 23 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| October 7 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 57325 is 1 mile from Chamberlain Municipal Airport, SD, which stands at 1,703 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 57325 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.