The official National Weather Service forecast for Winnsboro — 34.3807°N, 81.0865°W, population 4,710, 7.3 miles from I-77. Forecasts here are written by NWS CAE, this county’s forecast office.
| Fairfield County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 55 | 59 | 67 | 75 | 82 | 89 | 92 | 90 | 84 | 75 | 65 | 57 | 74 |
| Avg low °F | 33 | 36 | 42 | 49 | 58 | 66 | 70 | 69 | 63 | 51 | 41 | 35 | 51 |
| Precip in | 3.7 | 3.3 | 3.8 | 3.3 | 3.4 | 3.9 | 4.3 | 4.3 | 4.0 | 2.9 | 2.9 | 4.1 | 43.9 |
1996–2025 normals for Fairfield County — the climate division Winnsboro sits in. All-time county record high 106.7°F (1983-08-22); record low 0.7°F (1985-01-22). Source: NOAA / National Weather Service.