Frost dates for 57709 — Rapid City, SD
How Rapid City compares
- In 8 years out of 10, the last spring frost in Rapid City falls between April 27 and May 25, a 28-day window. The first fall frost falls between September 20 and October 18.
- The median last frost is 4 days later than the South Dakota median of May 6.
- Its 148-day growing season is longer than 42% of the 363 South Dakota places with a regular frost season (state median 149 days).
- The last frost is 9 days later than the zone 5b median of May 1. Hardiness zones measure winter cold, not season length, so use these dates rather than a zone 5b chart.
- The weather station records an average of 170 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 27 |
| 50% (median) | May 10 |
| 10% (safe for tender plants) | May 25 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 20 |
| 50% (median) | October 5 |
| 90% (late) | October 18 |
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 Rapid City, SD
Frost dates for 57709 — Rapid City, SD — last frost May 10, first frost Oct 5, zone 5b. whenisthelastfrost.com
When to plant vegetables in Rapid City, SD
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 15 – Mar 1 | Apr 12 – Apr 26 | — | — |
| Peppers | Mar 1 – Mar 15 | May 24 – Jun 7 | — | — |
| Eggplant | Mar 1 – Mar 15 | May 24 – Jun 7 | — | — |
| Tomatoes | Mar 15 – Mar 29 | May 17 – May 31 | — | — |
| Lettuce | Mar 15 – Mar 29 | Apr 19 – May 3 | Apr 12 – May 17 | Aug 10 – Sep 7 |
| Kale | Mar 15 – Mar 29 | Apr 12 – Apr 26 | Apr 12 – Apr 26 | Jul 27 – Aug 17 |
| Broccoli | Mar 15 – Mar 29 | Apr 26 – May 10 | — | Jun 29 – Jul 20 |
| Cabbage | Mar 15 – Mar 29 | Apr 19 – May 3 | — | Jun 29 – Jul 20 |
| Cauliflower | Mar 15 – Mar 29 | Apr 26 – May 10 | — | Jun 29 – Jul 20 |
| Okra | Mar 29 – Apr 12 | May 31 – Jun 14 | May 31 – Jun 14 | — |
| Basil | Mar 29 – Apr 12 | May 17 – May 31 | — | — |
| Peas | — | — | Mar 29 – Apr 19 | Jul 13 – Aug 3 |
| Spinach | — | — | Mar 29 – Apr 19 | Aug 10 – Aug 31 |
| Radishes | — | — | Apr 5 – May 17 | Aug 24 – Sep 14 |
| Cucumbers | Apr 12 – Apr 19 | May 24 – May 31 | May 17 – May 31 | Jul 20 – Aug 3 |
| Zucchini & Summer Squash | Apr 12 – Apr 19 | — | May 17 – May 31 | Jul 27 – Aug 10 |
| Winter Squash & Pumpkins | Apr 12 – Apr 19 | — | May 17 – May 31 | — |
| Melons & Watermelon | Apr 12 – Apr 19 | May 24 – Jun 7 | — | — |
| Carrots | — | — | Apr 19 – May 17 | Jul 13 – Jul 27 |
| Beets | — | — | Apr 19 – May 17 | Jul 27 – Aug 10 |
| Potatoes | — | — | Apr 19 – May 10 | — |
| Swiss Chard | — | — | Apr 26 – May 24 | Jul 27 – Aug 10 |
| Cilantro | — | — | Apr 26 – May 17 | Aug 10 – Aug 31 |
| Green Beans | — | — | May 17 – Jun 7 | Jul 20 – Aug 3 |
| Sweet Corn | — | — | May 17 – May 31 | — |
| Sweet Potatoes | — | May 24 – Jun 14 | — | — |
| Garlic | — | — | — | Sep 21 – Oct 26 |
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 Rapid City 4nw, SD weather station, 6 km away (elevation 3,478 ft (1,060 m)).
ZIP codes in Rapid City: 57701 57702 57703 57709
Frost dates near Rapid City
- Black Hawk May 10 · Oct 5
- Piedmont May 10 · Oct 5
- Box Elder May 12 · Oct 1
- Ellsworth Afb May 12 · Oct 1
- Keystone May 15 · Oct 1
- Nemo May 20 · Sep 25
- Hill City Jun 1 · Sep 10
- Hermosa May 15 · Oct 1
Frequently asked questions
When is the last frost in Rapid City, SD?
The median last spring frost in Rapid City, SD is May 10. There is still about a 10% chance of frost after May 25, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Rapid City, SD?
The median first fall frost is October 5, with about a 10% chance of frost before September 20.
How long is the growing season in Rapid City, SD?
About 148 days between the median last spring frost and first fall frost.
What planting zone is Rapid City, SD?
Rapid City, SD is in USDA hardiness zone 5b.