The official National Weather Service forecast for Fort Yates — 46.0869°N, 100.6301°W, 51.7 miles from I-94.
| Sioux County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 25 | 28 | 41 | 56 | 67 | 78 | 85 | 83 | 75 | 58 | 42 | 29 | 56 |
| Avg low °F | 5 | 7 | 18 | 29 | 41 | 52 | 58 | 55 | 46 | 33 | 19 | 9 | 31 |
| Precip in | 0.3 | 0.5 | 0.7 | 1.5 | 3.0 | 3.2 | 2.5 | 2.2 | 1.6 | 1.6 | 0.5 | 0.5 | 18.1 |
1996–2025 normals for Sioux County — the climate division Fort Yates sits in. All-time county record high 108.5°F (2002-06-29); record low -38.2°F (1966-01-29). Source: NOAA / National Weather Service.