Frost dates for 57783 — Spearfish, SD
How Spearfish compares
- In 8 years out of 10, the last spring frost in Spearfish falls between April 29 and May 25, a 26-day window. The first fall frost falls between September 21 and October 17.
- The median last frost is 6 days later than the South Dakota median of May 6.
- Its 143-day growing season is longer than 21% of the 363 South Dakota places with a regular frost season (state median 149 days).
- The last frost is 11 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 144 nights a year at or below 32°F.
- Compared with Rapid City, SD, 67 km away, the last frost here is 9 days later than there and the growing season is 15 days shorter.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 29 |
| 50% (median) | May 12 |
| 10% (safe for tender plants) | May 25 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 21 |
| 50% (median) | October 2 |
| 90% (late) | October 17 |
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 Spearfish, SD
Frost dates for 57783 — Spearfish, SD — last frost May 12, first frost Oct 2, zone 5b. whenisthelastfrost.com
When to plant vegetables in Spearfish, SD
| Crop | Start indoors | Transplant | Sow outdoors | Fall crop |
|---|---|---|---|---|
| Onions | Feb 17 – Mar 3 | Apr 14 – Apr 28 | — | — |
| Peppers | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Eggplant | Mar 3 – Mar 17 | May 26 – Jun 9 | — | — |
| Tomatoes | Mar 17 – Mar 31 | May 19 – Jun 2 | — | — |
| Lettuce | Mar 17 – Mar 31 | Apr 21 – May 5 | Apr 14 – May 19 | Aug 7 – Sep 4 |
| Kale | Mar 17 – Mar 31 | Apr 14 – Apr 28 | Apr 14 – Apr 28 | Jul 24 – Aug 14 |
| Broccoli | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 26 – Jul 17 |
| Cabbage | Mar 17 – Mar 31 | Apr 21 – May 5 | — | Jun 26 – Jul 17 |
| Cauliflower | Mar 17 – Mar 31 | Apr 28 – May 12 | — | Jun 26 – Jul 17 |
| Okra | Mar 31 – Apr 14 | Jun 2 – Jun 16 | Jun 2 – Jun 16 | — |
| Basil | Mar 31 – Apr 14 | May 19 – Jun 2 | — | — |
| Peas | — | — | Mar 31 – Apr 21 | Jul 10 – Jul 31 |
| Spinach | — | — | Mar 31 – Apr 21 | Aug 7 – Aug 28 |
| Radishes | — | — | Apr 7 – May 19 | Aug 21 – Sep 11 |
| Cucumbers | Apr 14 – Apr 21 | May 26 – Jun 2 | May 19 – Jun 2 | Jul 17 – Jul 31 |
| Zucchini & Summer Squash | Apr 14 – Apr 21 | — | May 19 – Jun 2 | Jul 24 – Aug 7 |
| Winter Squash & Pumpkins | Apr 14 – Apr 21 | — | May 19 – Jun 2 | — |
| Melons & Watermelon | Apr 14 – Apr 21 | May 26 – Jun 9 | — | — |
| Carrots | — | — | Apr 21 – May 19 | Jul 10 – Jul 24 |
| Beets | — | — | Apr 21 – May 19 | Jul 24 – Aug 7 |
| Potatoes | — | — | Apr 21 – May 12 | — |
| Swiss Chard | — | — | Apr 28 – May 26 | Jul 24 – Aug 7 |
| Cilantro | — | — | Apr 28 – May 19 | Aug 7 – Aug 28 |
| Green Beans | — | — | May 19 – Jun 9 | Jul 17 – Jul 31 |
| Sweet Corn | — | — | May 19 – Jun 2 | — |
| Sweet Potatoes | — | May 26 – Jun 16 | — | — |
| Garlic | — | — | — | Sep 18 – Oct 23 |
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 Spearfish, SD weather station, about 1 km away (elevation 3,632 ft (1,107 m)).
ZIP codes in Spearfish: 57783 57799
Frost dates near Spearfish
- Saint Onge May 12 · Oct 2
- Deadwood May 24 · Sep 25
- Whitewood May 24 · Sep 25
- Belle Fourche May 10 · Sep 30
- Lead May 18 · Sep 29
- Nisland May 8 · Oct 1
- Fort Meade May 8 · Oct 3
- Nemo May 20 · Sep 25
Frequently asked questions
When is the last frost in Spearfish, SD?
The median last spring frost in Spearfish, SD is May 12. 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 Spearfish, SD?
The median first fall frost is October 2, with about a 10% chance of frost before September 21.
How long is the growing season in Spearfish, SD?
About 143 days between the median last spring frost and first fall frost.
What planting zone is Spearfish, SD?
Spearfish, SD is in USDA hardiness zone 5b.