Bison, SD frost dates
How Bison compares
- In 8 years out of 10, the last spring frost in Bison falls between April 30 and May 24, a 24-day window. The first fall frost falls between September 16 and October 15.
- The median last frost is 4 days later than the South Dakota median of May 6.
- Its 144-day growing season is longer than 25% 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 171 nights a year at or below 32°F.
Frost probability
| Chance of frost after | Date |
|---|---|
| 90% (early) | April 30 |
| 50% (median) | May 10 |
| 10% (safe for tender plants) | May 24 |
| Chance of frost before | Date |
|---|---|
| 10% (early) | September 16 |
| 50% (median) | October 1 |
| 90% (late) | October 15 |
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 Bison, SD
Bison, SD frost dates — last frost May 10, first frost Oct 1, zone 4b. whenisthelastfrost.com
When to plant vegetables in Bison, 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 6 – Sep 3 |
| Kale | Mar 15 – Mar 29 | Apr 12 – Apr 26 | Apr 12 – Apr 26 | Jul 23 – Aug 13 |
| Broccoli | Mar 15 – Mar 29 | Apr 26 – May 10 | — | Jun 25 – Jul 16 |
| Cabbage | Mar 15 – Mar 29 | Apr 19 – May 3 | — | Jun 25 – Jul 16 |
| Cauliflower | Mar 15 – Mar 29 | Apr 26 – May 10 | — | Jun 25 – Jul 16 |
| 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 9 – Jul 30 |
| Spinach | — | — | Mar 29 – Apr 19 | Aug 6 – Aug 27 |
| Radishes | — | — | Apr 5 – May 17 | Aug 20 – Sep 10 |
| Cucumbers | Apr 12 – Apr 19 | May 24 – May 31 | May 17 – May 31 | Jul 16 – Jul 30 |
| Zucchini & Summer Squash | Apr 12 – Apr 19 | — | May 17 – May 31 | Jul 23 – Aug 6 |
| 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 9 – Jul 23 |
| Beets | — | — | Apr 19 – May 17 | Jul 23 – Aug 6 |
| Potatoes | — | — | Apr 19 – May 10 | — |
| Swiss Chard | — | — | Apr 26 – May 24 | Jul 23 – Aug 6 |
| Cilantro | — | — | Apr 26 – May 17 | Aug 6 – Aug 27 |
| Green Beans | — | — | May 17 – Jun 7 | Jul 16 – Jul 30 |
| Sweet Corn | — | — | May 17 – May 31 | — |
| Sweet Potatoes | — | May 24 – Jun 14 | — | — |
| Garlic | — | — | — | Sep 17 – Oct 22 |
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 Bison, SD weather station, 2 km away (elevation 2,779 ft (847 m)).
Frost dates near Bison
- Meadow May 10 · Oct 1
- Prairie City May 30 · Sep 11
- Lodgepole May 30 · Sep 11
- Reva May 20 · Sep 19
- Lemmon May 10 · Sep 30
- Keldron May 10 · Sep 30
- Ralph May 18 · Sep 23
- Mud Butte May 11 · Sep 28
- Faith May 6 · Oct 5
- Morristown May 20 · Sep 23
Frequently asked questions
When is the last frost in Bison, SD?
The median last spring frost in Bison, SD is May 10. There is still about a 10% chance of frost after May 24, so wait until then to plant frost-tender crops like tomatoes and peppers.
When is the first frost in Bison, SD?
The median first fall frost is October 1, with about a 10% chance of frost before September 16.
How long is the growing season in Bison, SD?
About 144 days between the median last spring frost and first fall frost.
What planting zone is Bison, SD?
Bison, SD is in USDA hardiness zone 4b.