The official National Weather Service forecast for Terra Alta — 39.4457°N, 79.5464°W, 15.5 miles from I-68.
| Preston County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 36 | 41 | 50 | 62 | 70 | 77 | 81 | 79 | 74 | 63 | 51 | 41 | 60 |
| Avg low °F | 20 | 22 | 29 | 38 | 47 | 55 | 60 | 58 | 52 | 41 | 31 | 25 | 40 |
| Precip in | 4.2 | 3.6 | 4.0 | 4.5 | 5.5 | 5.3 | 5.2 | 4.4 | 3.9 | 3.7 | 3.3 | 4.1 | 51.7 |
1996–2025 normals for Preston County — the climate division Terra Alta sits in. All-time county record high 96.7°F (1988-07-17); record low -21.8°F (1994-01-19). Source: NOAA / National Weather Service.