The official National Weather Service forecast for Erwin — 36.1451°N, 82.4168°W, population 8,678, 6.1 miles from I-26.
| Unicoi County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 44 | 49 | 56 | 66 | 73 | 79 | 82 | 81 | 76 | 66 | 56 | 48 | 65 |
| Avg low °F | 25 | 29 | 34 | 42 | 50 | 57 | 61 | 60 | 55 | 44 | 34 | 29 | 43 |
| Precip in | 4.4 | 4.0 | 3.9 | 4.2 | 4.8 | 4.3 | 5.3 | 4.6 | 3.7 | 3.4 | 3.5 | 4.3 | 50.4 |
1996–2025 normals for Unicoi County — the climate division Erwin sits in. All-time county record high 96.5°F (2012-07-01); record low -18.2°F (1985-01-22). Source: NOAA / National Weather Service.