The official National Weather Service forecast for Fort Benton — 47.8183°N, 110.6674°W, 38.1 miles from I-15.
| Chouteau County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 34 | 35 | 46 | 56 | 66 | 75 | 86 | 84 | 73 | 58 | 44 | 35 | 58 |
| Avg low °F | 11 | 12 | 21 | 30 | 39 | 47 | 53 | 51 | 43 | 32 | 21 | 13 | 31 |
| Precip in | 0.5 | 0.5 | 0.6 | 1.3 | 2.3 | 2.6 | 1.1 | 1.2 | 1.3 | 1.0 | 0.6 | 0.5 | 13.5 |
1996–2025 normals for Chouteau County — the climate division Fort Benton sits in. All-time county record high 108.9°F (1961-08-06); record low -45.3°F (1968-12-30). Source: NOAA / National Weather Service.