Ashton, SD frost dates
Last spring frostMay 11median date
First fall frostSep 27median date
Growing season139 daysfrost-free
Hardiness zone4bZone 4b
How Ashton compares
- In 8 years out of 10, the last spring frost in Ashton falls between April 29 and May 23, a 24-day window. The first fall frost falls between September 15 and October 7.
- The median last frost is 5 days later than the South Dakota median of May 6.
- Its 139-day growing season is longer than 10% of the 363 South Dakota places with a regular frost season (state median 149 days).
- The last frost is typical for zone 4b, where the median is May 8.
- The weather station records an average of 182 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 29 |
| 50% (median) | May 11 |
| 10% (safe for tender plants) | May 23 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 15 |
| 50% (median) | September 27 |
| 90% (late) | October 7 |
Frost here means 32°F (0°C). A median date means half of years have their last frost earlier and half later.
Planting calendar for Ashton, SD
Ashton, SD frost dates — last frost May 11, first frost Sep 27, zone 4b. whenisthelastfrost.com
Crop
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Start indoors: Feb 16 to Mar 2Transplant outside: Apr 13 to Apr 27
Start indoors: Mar 2 to Mar 16Transplant outside: May 25 to Jun 8
Start indoors: Mar 2 to Mar 16Transplant outside: May 25 to Jun 8
Start indoors: Mar 16 to Mar 30Transplant outside: May 18 to Jun 1
Start indoors: Mar 16 to Mar 30Transplant outside: Apr 20 to May 4Sow outdoors: Apr 13 to May 18Plant for fall: Aug 2 to Aug 30
Start indoors: Mar 16 to Mar 30Transplant outside: Apr 13 to Apr 27Sow outdoors: Apr 13 to Apr 27Plant for fall: Jul 19 to Aug 9
Start indoors: Mar 16 to Mar 30Transplant outside: Apr 27 to May 11Plant for fall: Jun 21 to Jul 12
Start indoors: Mar 16 to Mar 30Transplant outside: Apr 20 to May 4Plant for fall: Jun 21 to Jul 12
Start indoors: Mar 16 to Mar 30Transplant outside: Apr 27 to May 11Plant for fall: Jun 21 to Jul 12
Start indoors: Mar 30 to Apr 13Transplant outside: Jun 1 to Jun 15Sow outdoors: Jun 1 to Jun 15
Start indoors: Mar 30 to Apr 13Transplant outside: May 18 to Jun 1
Sow outdoors: Mar 30 to Apr 20Plant for fall: Jul 5 to Jul 26
Sow outdoors: Mar 30 to Apr 20Plant for fall: Aug 2 to Aug 23
Sow outdoors: Apr 6 to May 18Plant for fall: Aug 16 to Sep 6
Start indoors: Apr 13 to Apr 20Transplant outside: May 25 to Jun 1Sow outdoors: May 18 to Jun 1Plant for fall: Jul 12 to Jul 26
Start indoors: Apr 13 to Apr 20Sow outdoors: May 18 to Jun 1Plant for fall: Jul 19 to Aug 2
Start indoors: Apr 13 to Apr 20Sow outdoors: May 18 to Jun 1
Start indoors: Apr 13 to Apr 20Transplant outside: May 25 to Jun 8
Sow outdoors: Apr 20 to May 18Plant for fall: Jul 5 to Jul 19
Sow outdoors: Apr 20 to May 18Plant for fall: Jul 19 to Aug 2
Sow outdoors: Apr 20 to May 11
Sow outdoors: Apr 27 to May 25Plant for fall: Jul 19 to Aug 2
Sow outdoors: Apr 27 to May 18Plant for fall: Aug 2 to Aug 23
Sow outdoors: May 18 to Jun 8Plant for fall: Jul 12 to Jul 26
Sow outdoors: May 18 to Jun 1
Transplant outside: May 25 to Jun 15
Plant for fall: Sep 13 to Oct 18
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Ashton, SD
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 16 – Mar 2 | Apr 13 – Apr 27 | — | — |
| Peppers | Mar 2 – Mar 16 | May 25 – Jun 8 | — | — |
| Eggplant | Mar 2 – Mar 16 | May 25 – Jun 8 | — | — |
| Tomatoes | Mar 16 – Mar 30 | May 18 – Jun 1 | — | — |
| Lettuce | Mar 16 – Mar 30 | Apr 20 – May 4 | Apr 13 – May 18 | Aug 2 – Aug 30 |
| Kale | Mar 16 – Mar 30 | Apr 13 – Apr 27 | Apr 13 – Apr 27 | Jul 19 – Aug 9 |
| Broccoli | Mar 16 – Mar 30 | Apr 27 – May 11 | — | Jun 21 – Jul 12 |
| Cabbage | Mar 16 – Mar 30 | Apr 20 – May 4 | — | Jun 21 – Jul 12 |
| Cauliflower | Mar 16 – Mar 30 | Apr 27 – May 11 | — | Jun 21 – Jul 12 |
| Okra | Mar 30 – Apr 13 | Jun 1 – Jun 15 | Jun 1 – Jun 15 | — |
| Basil | Mar 30 – Apr 13 | May 18 – Jun 1 | — | — |
| Peas | — | — | Mar 30 – Apr 20 | Jul 5 – Jul 26 |
| Spinach | — | — | Mar 30 – Apr 20 | Aug 2 – Aug 23 |
| Radishes | — | — | Apr 6 – May 18 | Aug 16 – Sep 6 |
| Cucumbers | Apr 13 – Apr 20 | May 25 – Jun 1 | May 18 – Jun 1 | Jul 12 – Jul 26 |
| Zucchini & Summer Squash | Apr 13 – Apr 20 | — | May 18 – Jun 1 | Jul 19 – Aug 2 |
| Winter Squash & Pumpkins | Apr 13 – Apr 20 | — | May 18 – Jun 1 | — |
| Melons & Watermelon | Apr 13 – Apr 20 | May 25 – Jun 8 | — | — |
| Carrots | — | — | Apr 20 – May 18 | Jul 5 – Jul 19 |
| Beets | — | — | Apr 20 – May 18 | Jul 19 – Aug 2 |
| Potatoes | — | — | Apr 20 – May 11 | — |
| Swiss Chard | — | — | Apr 27 – May 25 | Jul 19 – Aug 2 |
| Cilantro | — | — | Apr 27 – May 18 | Aug 2 – Aug 23 |
| Green Beans | — | — | May 18 – Jun 8 | Jul 12 – Jul 26 |
| Sweet Corn | — | — | May 18 – Jun 1 | — |
| Sweet Potatoes | — | May 25 – Jun 15 | — | — |
| Garlic | — | — | — | Sep 13 – Oct 18 |
Dates come from the median frost dates and common extension-service timing. Adjust for your soil temperature, microclimate and the varieties you grow.
About these dates
Based on 1991–2020 NOAA climate normals for the Mellette 4 W, SD weather station, 19 km away (elevation 1,296 ft (395 m)).
Frost dates near Ashton
- Brentford May 6 · Sep 29
- Mellette May 11 · Sep 27
- Redfield May 8 · Oct 1
- Conde May 6 · Sep 29
- Turton May 7 · Oct 3
- Northville May 11 · Sep 27
- Mansfield May 11 · Sep 27
- Frankfort May 8 · Oct 1
- Stratford May 6 · Sep 29
- Warner May 8 · Sep 29
Frequently asked questions
When is the last frost in Ashton, SD?
The median last spring frost in Ashton, SD is May 11. There is still about a 10% chance of frost after May 23, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Ashton, SD?
The median first fall frost is September 27, with about a 10% chance of frost before September 15.
How long is the growing season in Ashton, SD?
About 139 days between the median last spring frost and first fall frost.
What planting zone is Ashton, SD?
Ashton, SD is in USDA hardiness zone 4b.