The official National Weather Service forecast for Smithville — 35.9606°N, 85.8141°W, population 4,825, 10.2 miles from I-40.
| DeKalb County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 48 | 52 | 62 | 71 | 78 | 86 | 88 | 88 | 83 | 72 | 61 | 52 | 70 |
| Avg low °F | 28 | 32 | 38 | 45 | 55 | 63 | 67 | 65 | 58 | 47 | 37 | 31 | 47 |
| Precip in | 4.9 | 5.1 | 5.3 | 4.9 | 5.0 | 5.0 | 5.1 | 3.9 | 4.0 | 3.3 | 3.7 | 5.5 | 55.7 |
1996–2025 normals for DeKalb County — the climate division Smithville sits in. All-time county record high 105.9°F (1952-07-28); record low -18.1°F (1985-01-21). Source: NOAA / National Weather Service.