The official National Weather Service forecast for Gainesville — 32.821°N, 88.1589°W, 6.7 miles from I-59. Forecasts here are written by NWS BMX, this county’s forecast office.
| Sumter County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 57 | 62 | 70 | 77 | 84 | 90 | 92 | 92 | 87 | 78 | 67 | 60 | 76 |
| Avg low °F | 35 | 39 | 45 | 51 | 60 | 68 | 71 | 70 | 65 | 53 | 42 | 37 | 53 |
| Precip in | 5.2 | 5.3 | 5.5 | 5.0 | 3.9 | 4.6 | 4.9 | 4.2 | 3.5 | 3.0 | 3.7 | 5.0 | 53.8 |
1996–2025 normals for Sumter County — the climate division Gainesville sits in. All-time county record high 104.2°F (1952-07-25); record low 0.4°F (1985-01-21). Source: NOAA / National Weather Service.