USDA Hardiness Zone 4b
Frost Dates for 57042 — Madison, South Dakota
NOAA 1991–2020 normals from Madison 2SE, SD (1,643 ft), 2 miles east.
Updated
In Madison, the last spring frost (32°F) is around May 5 in half of years and has passed by May 18 in nine years out of ten. The first fall frost comes around September 30, as early as September 18 one year in ten, leaving a typical freeze-free season of 148 days (NOAA, Madison 2SE, SD).
- Last spring frost
- May 5
- First fall frost
- September 30
- 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 15
- Last snow
- March 26
- Winters with snow
- 100%
- Snow per year
- 36.8"
median, 1991–2020
median, 1991–2020
29 of 29 observed
NOAA normal
Frost risk by date in Madison
Half of springs at Madison 2SE, SD see their last 32°F night by May 5; only one in ten is past it by April 22, and one in ten still has one after May 18. Planting tender crops after May 11 leaves a 30% risk of a frost on them, after May 14 20%, and after May 18 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 30 in half of years, as early as September 18 one year in ten, and holds off past October 13 one year in ten. A hard freeze of 28°F follows 10 days later, around October 10; in spring the one-in-ten date for 28°F is May 10, 8 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 164 days one year in ten and falls short of 129 one year in ten. On average 170 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 14, and return around September 23. 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 2 | May 6 | May 9 | May 12 | May 14 | May 18 | May 21 | May 25 | May 29 |
| 32°F | Apr 22 | Apr 27 | Apr 30 | May 2 | May 5 | May 7 | May 11 | May 14 | May 18 |
| 28°F | Apr 12 | Apr 16 | Apr 20 | Apr 24 | Apr 27 | Apr 30 | May 2 | May 5 | May 10 |
| 24°F | Apr 3 | Apr 7 | Apr 10 | Apr 13 | Apr 16 | Apr 20 | Apr 23 | Apr 27 | May 1 |
| 20°F | Mar 22 | Mar 30 | Apr 2 | Apr 5 | Apr 8 | Apr 11 | Apr 14 | Apr 18 | Apr 23 |
| 16°F | Mar 13 | Mar 19 | Mar 24 | Mar 29 | Apr 1 | Apr 3 | Apr 6 | Apr 11 | Apr 17 |
| Low | 10% | 20% | 30% | 40% | 50% | 60% | 70% | 80% | 90% |
|---|---|---|---|---|---|---|---|---|---|
| 36°F | Sep 10 | Sep 15 | Sep 18 | Sep 20 | Sep 23 | Sep 26 | Sep 28 | Oct 1 | Oct 5 |
| 32°F | Sep 18 | Sep 22 | Sep 26 | Sep 28 | Sep 30 | Oct 3 | Oct 5 | Oct 9 | Oct 13 |
| 28°F | Sep 26 | Sep 30 | Oct 3 | Oct 6 | Oct 10 | Oct 13 | Oct 16 | Oct 19 | Oct 23 |
| 24°F | Oct 5 | Oct 11 | Oct 15 | Oct 18 | Oct 21 | Oct 24 | Oct 26 | Oct 29 | Nov 3 |
| 20°F | Oct 16 | Oct 22 | Oct 25 | Oct 28 | Oct 31 | Nov 2 | Nov 4 | Nov 7 | Nov 12 |
| 16°F | Oct 26 | Oct 31 | Nov 2 | Nov 5 | Nov 7 | Nov 10 | Nov 13 | Nov 17 | Nov 23 |
Freeze probabilities 1991–2020 at Madison 2SE, 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 57042 →Compare Madison with another place →
Weather by month in Madison
July is the warmest month at Madison 2SE, SD, averaging 83°F by day and 61°F at night; January is the coldest at 24°F and 5°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 68% of years.
Warmth for growing adds up to 2,597 growing degree days a year (base 50°F), fewer than at 65% of the 49 South Dakota stations. 33% of them (851) have built up by the end of June, and July adds the most, 685. Precipitation totals 26.4 inches a year, most in June (4.2") and least in January (0.5"); May to September bring 67% of it.
| Month | High °F | Low °F | Precip. in | 32°F night | Nights ≤ 32°F | GDD 50°F |
|---|---|---|---|---|---|---|
| Jan | 24 | 5 | 0.5 | 100% | 31 | 0 |
| Feb | 29 | 10 | 0.7 | 100% | 28 | 0 |
| Mar | 41 | 22 | 1.0 | 100% | 26 | 9 |
| Apr | 56 | 33 | 2.7 | 100% | 14 | 63 |
| May | 68 | 46 | 3.7 | 68% | 2 | 256 |
| Jun | 78 | 57 | 4.2 | 0% | 0 | 522 |
| Jul | 83 | 61 | 3.3 | 0% | 0 | 685 |
| Aug | 81 | 58 | 3.4 | 0% | 0 | 609 |
| Sep | 73 | 50 | 3.2 | 51% | 1 | 355 |
| Oct | 59 | 36 | 2.2 | 100% | 12 | 89 |
| Nov | 42 | 23 | 0.9 | 100% | 26 | 8 |
| Dec | 29 | 11 | 0.6 | 100% | 31 | 0 |
Monthly normals 1991–2020 at Madison 2SE, SD (1,643 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, Flandreau, SD, 27 miles east of Madison, has the same 50% last-frost date, a first frost 1 day later (October 1).
When it snows in Madison, South Dakota
The first measurable snow (0.1 inch or more) in Madison usually arrives around November 15, and the last of the season around March 26. Those are the middle dates across the winters of 1991–2020 at Madison 2SE, SD, 2.1 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 40 days after the last snow.
Planting calendar for 57042
| When | What to do |
|---|---|
| February 24 – March 10 | Start peppers and aubergines indoorsThey need eight to ten weeks under lights before they can go out. |
| March 10 – March 24 | Start tomatoes indoorsSix to eight weeks gives a transplant big enough to set fruit early. |
| April 7 – April 21 | Sow peas, spinach, lettuce, radish outdoorsThese tolerate light frost and prefer to germinate in cool soil. |
| May 5 onward | Transplant tomatoes, peppers, basil, squash, cucumbersThe average last freeze has passed — still watch the actual forecast. |
| by July 8 | Sow the autumn crop of carrots, beets and brassicasThey need about twelve weeks to size up before growth stops. |
| by September 16 | Harvest tender crops, or be ready to cover themA first freeze two weeks early is well within normal variation. |
| September 30 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 57042 is 2 miles from Madison 2SE, SD, which stands at 1,643 feet, the nearest NOAA station that publishes freeze probabilities for 1991–2020. The 2023 USDA Plant Hardiness Zone Map lists ZIP 57042 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.