The official National Weather Service forecast for Bethlehem — 39.392°N, 80.2806°W, 4.1 miles from I-79.
| Harrison County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 40 | 45 | 55 | 66 | 75 | 82 | 85 | 83 | 78 | 67 | 55 | 45 | 65 |
| Avg low °F | 22 | 25 | 32 | 40 | 49 | 58 | 62 | 61 | 54 | 43 | 33 | 27 | 42 |
| Precip in | 3.6 | 3.3 | 3.7 | 4.1 | 5.0 | 5.1 | 5.1 | 4.1 | 3.6 | 3.4 | 3.0 | 3.6 | 47.6 |
1996–2025 normals for Harrison County — the climate division Bethlehem sits in. All-time county record high 100.8°F (1988-07-17); record low -23.2°F (1994-01-19). Source: NOAA / National Weather Service.