Average Soil Temperature in Spearfish, SD for September 2026
Data from Sundance 8 NNW (28.4 mi away) • 25 of 30 days reported
Monthly Summary by Depth
2" depth
60.3°F
avg
56.7°F – 66.4°F
25 days
4" depth
59.8°F
avg
56.1°F – 65.8°F
25 days
8" depth
59.7°F
avg
57°F – 63.7°F
25 days
20" depth
57.9°F
avg
56.3°F – 59.7°F
25 days
40" depth
57.8°F
avg
56.7°F – 58.6°F
25 days
Daily Readings
| Date | 2" | 4" | 8" | 20" | 40" |
|---|---|---|---|---|---|
| Sep 1 | 60.4°F | 59.7°F | 60.4°F | 59°F | 58.6°F |
| Sep 2 | 61.5°F | 61°F | 60.3°F | 58.6°F | 58.5°F |
| Sep 3 | 63°F | 62.4°F | 61.2°F | 58.5°F | 58.3°F |
| Sep 4 | 63.5°F | 63°F | 61.5°F | 58.6°F | 58.3°F |
| Sep 5 | 64.9°F | 64.2°F | 62.4°F | 59°F | 58.3°F |
| Sep 6 | 66.4°F | 65.8°F | 63.3°F | 59.2°F | 58.3°F |
| Sep 7 | 65.5°F | 65.1°F | 63.7°F | 59.7°F | 58.5°F |
| Sep 8 | 62.1°F | 61.5°F | 62.1°F | 59.7°F | 58.6°F |
| Sep 9 | 60.6°F | 60.4°F | 60.8°F | 59.4°F | 58.6°F |
| Sep 10 | 60.3°F | 59.9°F | 59.9°F | 58.6°F | 58.5°F |
| Sep 11 | 61.9°F | 61°F | 60.4°F | 58.3°F | 58.3°F |
| Sep 12 | 60.1°F | 59.5°F | 59.9°F | 58.3°F | 58.3°F |
| Sep 13 | 60.1°F | 59.5°F | 59.2°F | 57.9°F | 58.1°F |
| Sep 14 | 60.4°F | 59.9°F | 60.1°F | 57.7°F | 57.9°F |
| Sep 15 | 56.7°F | 56.1°F | 58.1°F | 57.6°F | 57.7°F |
| Sep 16 | 58.1°F | 57.4°F | 57.7°F | 57°F | 57.7°F |
| Sep 17 | 58.3°F | 57.9°F | 57.9°F | 57°F | 57.4°F |
| Sep 18 | 60.4°F | 59.7°F | 58.8°F | 56.8°F | 57.2°F |
| Sep 19 | 59.4°F | 59°F | 59.2°F | 57.2°F | 57.2°F |
| Sep 20 | 57°F | 56.8°F | 58.1°F | 57°F | 57.2°F |
| Sep 21 | 56.8°F | 56.7°F | 57°F | 56.7°F | 57.2°F |
| Sep 22 | 57.4°F | 57.2°F | 57.2°F | 56.5°F | 57°F |
| Sep 23 | 58.1°F | 58.1°F | 57.7°F | 56.5°F | 56.8°F |
| Sep 24 | 57.2°F | 56.8°F | 57.4°F | 56.5°F | 56.8°F |
| Sep 25 | 57.2°F | 57°F | 57.2°F | 56.3°F | 56.7°F |