The official National Weather Service forecast for Martinsburg — 39.4562°N, 77.9639°W, 1.9 miles from I-81.
| Berkeley County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 41 | 45 | 54 | 66 | 75 | 83 | 87 | 85 | 79 | 67 | 55 | 45 | 65 |
| Avg low °F | 23 | 25 | 32 | 41 | 50 | 59 | 63 | 62 | 55 | 43 | 34 | 27 | 43 |
| Precip in | 2.6 | 2.2 | 3.0 | 3.4 | 4.5 | 3.9 | 3.8 | 3.3 | 4.0 | 3.0 | 2.6 | 2.9 | 39.2 |
1996–2025 normals for Berkeley County — the climate division Martinsburg sits in. All-time county record high 104.6°F (1988-07-17); record low -14.0°F (1994-01-19). Source: NOAA / National Weather Service.