The official National Weather Service forecast for Hallsville — 32.5043°N, 94.5741°W, 3.3 miles from I-20. Forecasts here are written by NWS SHV, this county’s forecast office.
| Harrison County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 58 | 61 | 70 | 77 | 84 | 90 | 94 | 94 | 89 | 79 | 68 | 60 | 77 |
| Avg low °F | 36 | 40 | 47 | 54 | 63 | 70 | 73 | 73 | 66 | 54 | 45 | 39 | 55 |
| Precip in | 4.4 | 4.0 | 5.0 | 4.7 | 5.0 | 4.2 | 3.5 | 3.1 | 3.4 | 4.1 | 4.2 | 4.5 | 50.1 |
1996–2025 normals for Harrison County — the climate division Hallsville sits in. All-time county record high 108.9°F (2011-08-04); record low -1.1°F (1951-02-02). Source: NOAA / National Weather Service.