The official National Weather Service forecast for Glenville — 38.9343°N, 80.8376°W, 10.8 miles from I-79.
| Gilmer County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 42 | 47 | 56 | 68 | 76 | 83 | 85 | 85 | 79 | 68 | 56 | 47 | 66 |
| Avg low °F | 23 | 26 | 32 | 40 | 50 | 58 | 63 | 62 | 55 | 44 | 33 | 28 | 43 |
| Precip in | 3.6 | 3.3 | 3.9 | 3.9 | 5.2 | 4.8 | 5.0 | 4.0 | 3.5 | 3.3 | 3.0 | 3.6 | 47.1 |
1996–2025 normals for Gilmer County — the climate division Glenville sits in. All-time county record high 102.5°F (1988-07-17); record low -22.2°F (1994-01-19). Source: NOAA / National Weather Service.