Last frost date in Spearfish, South Dakota
May 12
Average last frost in spring. In an early year (1 in 10) it's over by April 29; in a late year (1 in 10) it comes after May 25.
October 2
Average first frost in fall. 1 year in 10 it comes by September 21.
Source: NOAA U.S. Climate Normals 1991–2020, station Spearfish (USC00397882), 2.8 miles from Spearfish, elevation 3,633 ft. NOAA National Centers for Environmental Information. These are long-term averages, not a forecast.
| Early year | Average | Late year | |
|---|---|---|---|
| Last frost in spring | Apr 29 | May 12 | May 25 |
| First frost in fall | Sept 21 | Oct 2 | Oct 17 |
Frost-free days in an average year: 143
| Chance in a year | Average last in spring | Average first in fall | |
|---|---|---|---|
| Light frost (36°F) | Every year | May 22 | Sept 25 |
| Frost (32°F) | Every year | May 12 | Oct 2 |
| Hard freeze (28°F) | Every year | Apr 30 | Oct 12 |
Nights at 32°F or colder in an average year: 144
What to plant now in Spearfish
- Spring planting calendar for an average last frost around May 10 Spearfish: May 12
- Fall planting calendar for an average first frost around September 30 Spearfish: October 2
Planting dates: USDA Home and Garden Bulletin No. 9 (1967), “Suburban and Farm Vegetable Gardens,” tables 4 and 5. How we match the table.
Nearby in South Dakota
- Rapid City 41 mi · last frost May 3
- Box Elder 45 mi · last frost May 12
- Pierre 173 mi · last frost May 6
- Aberdeen 270 mi · last frost May 8
- Huron 277 mi · last frost May 6