Belle Fourche, SD frost dates
How Belle Fourche compares
- In 8 years out of 10, the last spring frost in Belle Fourche falls between April 27 and May 25, a 28-day window. The first fall frost falls between September 16 and October 13.
- The median last frost is 4 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 typical for zone 4b, where the median is May 8.
- The weather station records an average of 167 nights a year at or below 32°F.
- Compared with Rapid City, SD, 81 km away, the last frost here is 7 days later than there and the growing season is 15 days shorter.
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 16 |
| 50% (median) | September 30 |
| 90% (late) | October 13 |
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 Belle Fourche, SD
Belle Fourche, SD frost dates — last frost May 10, first frost Sep 30, zone 4b. whenisthelastfrost.com
When to plant vegetables in Belle Fourche, 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 5 – Sep 2 |
| Kale | Mar 15 – Mar 29 | Apr 12 – Apr 26 | Apr 12 – Apr 26 | Jul 22 – Aug 12 |
| Broccoli | Mar 15 – Mar 29 | Apr 26 – May 10 | — | Jun 24 – Jul 15 |
| Cabbage | Mar 15 – Mar 29 | Apr 19 – May 3 | — | Jun 24 – Jul 15 |
| Cauliflower | Mar 15 – Mar 29 | Apr 26 – May 10 | — | Jun 24 – Jul 15 |
| 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 8 – Jul 29 |
| Spinach | — | — | Mar 29 – Apr 19 | Aug 5 – Aug 26 |
| Radishes | — | — | Apr 5 – May 17 | Aug 19 – Sep 9 |
| Cucumbers | Apr 12 – Apr 19 | May 24 – May 31 | May 17 – May 31 | Jul 15 – Jul 29 |
| Zucchini & Summer Squash | Apr 12 – Apr 19 | — | May 17 – May 31 | Jul 22 – Aug 5 |
| 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 8 – Jul 22 |
| Beets | — | — | Apr 19 – May 17 | Jul 22 – Aug 5 |
| Potatoes | — | — | Apr 19 – May 10 | — |
| Swiss Chard | — | — | Apr 26 – May 24 | Jul 22 – Aug 5 |
| Cilantro | — | — | Apr 26 – May 17 | Aug 5 – Aug 26 |
| Green Beans | — | — | May 17 – Jun 7 | Jul 15 – Jul 29 |
| Sweet Corn | — | — | May 17 – May 31 | — |
| Sweet Potatoes | — | May 24 – Jun 14 | — | — |
| Garlic | — | — | — | Sep 16 – Oct 21 |
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 Belle Fourche, SD weather station, about 1 km away (elevation 3,022 ft (921 m)).
Frost dates near Belle Fourche
- Saint Onge May 12 · Oct 2
- Spearfish May 12 · Oct 2
- Nisland May 8 · Oct 1
- Whitewood May 24 · Sep 25
- Deadwood May 24 · Sep 25
- Newell May 8 · Oct 1
- Vale May 8 · Oct 1
- Fort Meade May 8 · Oct 3
- Lead May 18 · Sep 29
- Sturgis May 8 · Oct 3
Frequently asked questions
When is the last frost in Belle Fourche, SD?
The median last spring frost in Belle Fourche, 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 Belle Fourche, SD?
The median first fall frost is September 30, with about a 10% chance of frost before September 16.
How long is the growing season in Belle Fourche, SD?
About 143 days between the median last spring frost and first fall frost.
What planting zone is Belle Fourche, SD?
Belle Fourche, SD is in USDA hardiness zone 4b.