The official National Weather Service forecast for Oak Grove — 36.4118°N, 82.4246°W, 5.6 miles from I-26.
| Washington County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 47 | 52 | 61 | 70 | 77 | 84 | 86 | 86 | 81 | 71 | 60 | 51 | 69 |
| Avg low °F | 27 | 31 | 36 | 44 | 52 | 60 | 64 | 63 | 57 | 46 | 35 | 30 | 45 |
| Precip in | 3.8 | 3.8 | 3.8 | 4.1 | 4.4 | 4.0 | 5.1 | 4.2 | 3.3 | 2.8 | 3.0 | 3.7 | 46.0 |
1996–2025 normals for Washington County — the climate division Oak Grove sits in. All-time county record high 101.7°F (2012-06-30); record low -15.3°F (1985-01-22). Source: NOAA / National Weather Service.