The official National Weather Service forecast for Zanesville — 40.9173°N, 85.2805°W, 2.3 miles from I-69. Forecasts here are written by NWS IWX, this county’s forecast office.
| Allen County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 33 | 37 | 49 | 61 | 72 | 81 | 84 | 82 | 77 | 64 | 50 | 38 | 61 |
| Avg low °F | 18 | 21 | 29 | 39 | 50 | 60 | 62 | 61 | 54 | 43 | 32 | 24 | 41 |
| Precip in | 2.4 | 2.1 | 2.7 | 3.6 | 4.6 | 4.2 | 4.1 | 3.8 | 3.0 | 2.9 | 2.6 | 2.5 | 38.5 |
1996–2025 normals for Allen County — the climate division Zanesville sits in. All-time county record high 105.4°F (2012-06-29); record low -21.1°F (1985-01-21). Source: NOAA / National Weather Service.