In South Dakota, the last spring frost usually comes between May 6 and May 19, and the first fall frost between September 22 and October 3, depending on where you live. Most of South Dakota is in USDA hardiness zones 4a to 5a.
Find the frost dates for your ZIP code
Frost dates from NOAA 1991–2020 U.S. Climate Normals, nearest weather station. Zones derived from the 2023 USDA Plant Hardiness Zone Map data (PRISM Climate Group, Oregon State University). This is not the official USDA Plant Hardiness Zone Map.
Frost dates for South Dakota cities
Dates come from the NOAA weather station closest to each city. The last spring frost and first fall frost are the typical dates, with a 30% chance of frost after (or before) them. The safer planting date has only a 10% chance of a later spring frost: use it for tender plants like tomatoes, peppers and basil.
| City | Zone | Last frost | Safer date | First frost |
|---|---|---|---|---|
| Sioux Falls | 5a | May 6 | May 14 | Sep. 30 |
| Rapid City | 5b | May 9 | May 17 | Oct. 1 |
| Aberdeen | 4a | May 14 | May 21 | Sep. 24 |
| Brookings | 4b | May 11 | May 19 | Sep. 25 |
| Watertown | 4b | May 12 | May 20 | Sep. 26 |
| Mitchell | 5a | May 6 | May 15 | Sep. 30 |
| Yankton | 5a | May 2 | May 10 | Oct. 4 |
| Pierre | 4b | May 11 | May 19 | Oct. 1 |
| Huron | 4b | May 12 | May 20 | Sep. 27 |
| Spearfish | 5b | May 17 | May 25 | Sep. 29 |
Frost dates vary a lot across South Dakota. Among the cities above, Yankton has the earliest last frost (around May 2) and Spearfish the latest (around May 17), about 2 weeks apart. Elevation, nearby water and local terrain all make a difference, so use the dates for the place closest to you, or look up your ZIP code.
Growing zones in South Dakota
Most of South Dakota is in USDA hardiness zones 4a to 5a. A typical frost-free growing season lasts about 157 days, longer in the warmest areas and shorter in the coldest.
Find planting dates for the main zones in South Dakota:
- Zone 4 (about 52% of ZIP codes): Tomatoes, Peppers, Potatoes, Lettuce, Green beans, Cucumbers, Garlic, Tulips
- Zone 5 (about 48% of ZIP codes): Tomatoes, Peppers, Potatoes, Lettuce, Green beans, Cucumbers, Garlic, Tulips
See all crops in our planting guides, or build a planting calendar for your ZIP code.
How to use frost dates
- Cool-season crops such as peas, lettuce, spinach and onions can go in several weeks before your last spring frost.
- Warm-season crops such as tomatoes, peppers, squash and beans wait until after it, when the soil has warmed.
- Fall crops are timed back from your first fall frost, and garlic and tulips are planted around it.
- Frost dates are averages. Check the forecast before setting out tender plants.
Frequently asked questions
When is the last frost in South Dakota?
It depends on where you live. Across most of South Dakota, the last spring frost comes between May 6 and May 19. In Sioux Falls, it is around May 6.
When is the first frost in South Dakota?
Across most of South Dakota, the first fall frost comes between September 22 and October 3. In Sioux Falls, it is around September 30.
What planting zone is South Dakota?
Most of South Dakota is in USDA hardiness zones 4a to 5a. Enter your ZIP code above to find your exact zone.
When can I plant tomatoes in South Dakota?
Plant tomatoes outside after your last frost, once nights stay above 50 °F. In Sioux Falls, the safer date, with only a 10% chance of a later frost, is around May 14. See when to plant tomatoes in zone 5.
Sources. Frost dates come from the nearest NOAA weather station to each city or ZIP code. Zones come from the 2023 USDA Plant Hardiness Zone Map ZIP code data. Our zone lookup is not the official USDA map.