The official National Weather Service forecast for Fincastle — 36.4098°N, 84.0477°W, 10.8 miles from I-75.
| Campbell County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 44 | 50 | 59 | 68 | 76 | 82 | 84 | 83 | 79 | 69 | 57 | 48 | 67 |
| Avg low °F | 26 | 30 | 36 | 44 | 53 | 60 | 64 | 63 | 57 | 46 | 35 | 30 | 45 |
| Precip in | 4.9 | 5.4 | 5.1 | 4.9 | 4.3 | 4.8 | 5.4 | 4.0 | 3.9 | 3.4 | 3.9 | 5.6 | 55.6 |
1996–2025 normals for Campbell County — the climate division Fincastle sits in. All-time county record high 102.2°F (2012-06-30); record low -19.9°F (1985-01-21). Source: NOAA / National Weather Service.