The official National Weather Service forecast for Zanesville — 39.9404°N, 82.0132°W, population 42,301, 1.2 miles from I-70.
| Muskingum County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 37 | 42 | 52 | 64 | 74 | 81 | 84 | 83 | 77 | 66 | 53 | 42 | 63 |
| Avg low °F | 21 | 23 | 31 | 40 | 50 | 58 | 62 | 61 | 54 | 43 | 33 | 26 | 42 |
| Precip in | 3.0 | 2.7 | 3.4 | 4.1 | 4.4 | 4.7 | 4.1 | 3.6 | 3.3 | 3.0 | 2.8 | 3.2 | 42.3 |
1996–2025 normals for Muskingum County — the climate division Zanesville sits in. All-time county record high 100.4°F (1953-09-03); record low -26.8°F (1994-01-19). Source: NOAA / National Weather Service.