The official National Weather Service forecast for Portsmouth — 38.7317°N, 82.9977°W, population 35,346, 68.4 miles from I-77.
| Scioto County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 41 | 46 | 56 | 67 | 76 | 83 | 86 | 85 | 80 | 68 | 56 | 46 | 66 |
| Avg low °F | 23 | 26 | 33 | 42 | 51 | 60 | 64 | 62 | 55 | 44 | 34 | 28 | 44 |
| Precip in | 3.2 | 3.1 | 3.8 | 4.2 | 4.7 | 4.2 | 4.5 | 3.2 | 3.5 | 3.1 | 2.6 | 3.5 | 43.6 |
1996–2025 normals for Scioto County — the climate division Portsmouth sits in. All-time county record high 103.6°F (2012-07-08); record low -24.0°F (1994-01-19). Source: NOAA / National Weather Service.