The official National Weather Service forecast for Harlem — 33.4146°N, 82.3126°W, 8.1 miles from I-20. Forecasts here are written by NWS CAE, this county’s forecast office.
| Columbia County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 57 | 61 | 68 | 76 | 83 | 89 | 92 | 90 | 85 | 76 | 67 | 59 | 75 |
| Avg low °F | 35 | 38 | 44 | 50 | 59 | 67 | 71 | 70 | 64 | 53 | 42 | 37 | 52 |
| Precip in | 3.8 | 3.7 | 4.2 | 3.2 | 3.6 | 4.2 | 4.3 | 4.4 | 3.8 | 2.4 | 2.8 | 4.1 | 44.5 |
1996–2025 normals for Columbia County — the climate division Harlem sits in. All-time county record high 107.0°F (2012-07-01); record low -1.0°F (1985-01-21). Source: NOAA / National Weather Service.