Custer, SD frost dates
Last spring frostMay 15median date
First fall frostSep 29median date
Growing season137 daysfrost-free
Hardiness zone5aZone 5a
How Custer compares
- In 8 years out of 10, the last spring frost in Custer falls between May 4 and May 30, a 26-day window. The first fall frost falls between September 13 and October 11.
- The median last frost is 9 days later than the South Dakota median of May 6.
- Its 137-day growing season is longer than 8% of the 363 South Dakota places with a regular frost season (state median 149 days).
- The last frost is 12 days later than the zone 5a median of May 3. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5a chart.
- The weather station records an average of 172 nights a year at or below 32°F.
- Compared with Rapid City, SD, 48 km away, the last frost here is 12 days later than there and the growing season is 21 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | May 4 |
| 50% (median) | May 15 |
| 10% (safe for tender plants) | May 30 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 13 |
| 50% (median) | September 29 |
| 90% (late) | October 11 |
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 Custer, SD
Custer, SD frost dates — last frost May 15, first frost Sep 29, zone 5a. whenisthelastfrost.com
Crop
JFMAMJJASOND
Start indoors: Feb 20 to Mar 6Transplant outside: Apr 17 to May 1
Start indoors: Mar 6 to Mar 20Transplant outside: May 29 to Jun 12
Start indoors: Mar 6 to Mar 20Transplant outside: May 29 to Jun 12
Start indoors: Mar 20 to Apr 3Transplant outside: May 22 to Jun 5
Start indoors: Mar 20 to Apr 3Transplant outside: Apr 24 to May 8Sow outdoors: Apr 17 to May 22Plant for fall: Aug 4 to Sep 1
Start indoors: Mar 20 to Apr 3Transplant outside: Apr 17 to May 1Sow outdoors: Apr 17 to May 1Plant for fall: Jul 21 to Aug 11
Start indoors: Mar 20 to Apr 3Transplant outside: May 1 to May 15Plant for fall: Jun 23 to Jul 14
Start indoors: Mar 20 to Apr 3Transplant outside: Apr 24 to May 8Plant for fall: Jun 23 to Jul 14
Start indoors: Mar 20 to Apr 3Transplant outside: May 1 to May 15Plant for fall: Jun 23 to Jul 14
Start indoors: Apr 3 to Apr 17Transplant outside: Jun 5 to Jun 19Sow outdoors: Jun 5 to Jun 19
Start indoors: Apr 3 to Apr 17Transplant outside: May 22 to Jun 5
Sow outdoors: Apr 3 to Apr 24Plant for fall: Jul 7 to Jul 28
Sow outdoors: Apr 3 to Apr 24Plant for fall: Aug 4 to Aug 25
Sow outdoors: Apr 10 to May 22Plant for fall: Aug 18 to Sep 8
Start indoors: Apr 17 to Apr 24Transplant outside: May 29 to Jun 5Sow outdoors: May 22 to Jun 5Plant for fall: Jul 14 to Jul 28
Start indoors: Apr 17 to Apr 24Sow outdoors: May 22 to Jun 5Plant for fall: Jul 21 to Aug 4
Start indoors: Apr 17 to Apr 24Sow outdoors: May 22 to Jun 5
Start indoors: Apr 17 to Apr 24Transplant outside: May 29 to Jun 12
Sow outdoors: Apr 24 to May 22Plant for fall: Jul 7 to Jul 21
Sow outdoors: Apr 24 to May 22Plant for fall: Jul 21 to Aug 4
Sow outdoors: Apr 24 to May 15
Sow outdoors: May 1 to May 29Plant for fall: Jul 21 to Aug 4
Sow outdoors: May 1 to May 22Plant for fall: Aug 4 to Aug 25
Sow outdoors: May 22 to Jun 12Plant for fall: Jul 14 to Jul 28
Sow outdoors: May 22 to Jun 5
Transplant outside: May 29 to Jun 19
Plant for fall: Sep 15 to Oct 20
Start indoorsTransplant outsideSow outdoorsPlant for fallMedian frost dates
When to plant vegetables in Custer, SD
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 20 – Mar 6 | Apr 17 – May 1 | — | — |
| Peppers | Mar 6 – Mar 20 | May 29 – Jun 12 | — | — |
| Eggplant | Mar 6 – Mar 20 | May 29 – Jun 12 | — | — |
| Tomatoes | Mar 20 – Apr 3 | May 22 – Jun 5 | — | — |
| Lettuce | Mar 20 – Apr 3 | Apr 24 – May 8 | Apr 17 – May 22 | Aug 4 – Sep 1 |
| Kale | Mar 20 – Apr 3 | Apr 17 – May 1 | Apr 17 – May 1 | Jul 21 – Aug 11 |
| Broccoli | Mar 20 – Apr 3 | May 1 – May 15 | — | Jun 23 – Jul 14 |
| Cabbage | Mar 20 – Apr 3 | Apr 24 – May 8 | — | Jun 23 – Jul 14 |
| Cauliflower | Mar 20 – Apr 3 | May 1 – May 15 | — | Jun 23 – Jul 14 |
| Okra | Apr 3 – Apr 17 | Jun 5 – Jun 19 | Jun 5 – Jun 19 | — |
| Basil | Apr 3 – Apr 17 | May 22 – Jun 5 | — | — |
| Peas | — | — | Apr 3 – Apr 24 | Jul 7 – Jul 28 |
| Spinach | — | — | Apr 3 – Apr 24 | Aug 4 – Aug 25 |
| Radishes | — | — | Apr 10 – May 22 | Aug 18 – Sep 8 |
| Cucumbers | Apr 17 – Apr 24 | May 29 – Jun 5 | May 22 – Jun 5 | Jul 14 – Jul 28 |
| Zucchini & Summer Squash | Apr 17 – Apr 24 | — | May 22 – Jun 5 | Jul 21 – Aug 4 |
| Winter Squash & Pumpkins | Apr 17 – Apr 24 | — | May 22 – Jun 5 | — |
| Melons & Watermelon | Apr 17 – Apr 24 | May 29 – Jun 12 | — | — |
| Carrots | — | — | Apr 24 – May 22 | Jul 7 – Jul 21 |
| Beets | — | — | Apr 24 – May 22 | Jul 21 – Aug 4 |
| Potatoes | — | — | Apr 24 – May 15 | — |
| Swiss Chard | — | — | May 1 – May 29 | Jul 21 – Aug 4 |
| Cilantro | — | — | May 1 – May 22 | Aug 4 – Aug 25 |
| Green Beans | — | — | May 22 – Jun 12 | Jul 14 – Jul 28 |
| Sweet Corn | — | — | May 22 – Jun 5 | — |
| Sweet Potatoes | — | May 29 – Jun 19 | — | — |
| Garlic | — | — | — | Sep 15 – Oct 20 |
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 Wind Cave, SD weather station, 12 km away (elevation 4,154 ft (1,266 m)).
Frost dates near Custer
- Pringle May 15 · Sep 29
- Fairburn May 15 · Sep 29
- Buffalo Gap May 15 · Sep 27
- Hermosa May 15 · Oct 1
- Keystone May 15 · Oct 1
- Hot Springs May 16 · Sep 27
- Hill City Jun 1 · Sep 10
- Oral May 15 · Sep 27
- Smithwick May 15 · Sep 27
- Rapid City May 3 · Oct 8
Frequently asked questions
When is the last frost in Custer, SD?
The median last spring frost in Custer, SD is May 15. There is still about a 10% chance of frost after May 30, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Custer, SD?
The median first fall frost is September 29, with about a 10% chance of frost before September 13.
How long is the growing season in Custer, SD?
About 137 days between the median last spring frost and first fall frost.
What planting zone is Custer, SD?
Custer, SD is in USDA hardiness zone 5a.