The official National Weather Service forecast for West Yellowstone — 44.6621°N, 111.1041°W, 56.9 miles from I-15.
| Gallatin County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 31 | 33 | 42 | 49 | 58 | 68 | 79 | 77 | 67 | 52 | 39 | 31 | 52 |
| Avg low °F | 13 | 13 | 20 | 26 | 34 | 41 | 48 | 46 | 39 | 30 | 20 | 13 | 29 |
| Precip in | 1.8 | 1.7 | 2.0 | 2.5 | 3.0 | 2.9 | 1.2 | 1.4 | 1.6 | 2.0 | 1.7 | 2.0 | 23.8 |
1996–2025 normals for Gallatin County — the climate division West Yellowstone sits in. All-time county record high 95.6°F (2026-07-13); record low -38.1°F (1962-01-09). Source: NOAA / National Weather Service.