The official National Weather Service forecast for Demopolis — 32.5176°N, 87.8364°W, population 6,227, 21.5 miles from I-20. Forecasts here are written by NWS BMX, this county’s forecast office.
| Marengo County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 58 | 62 | 71 | 77 | 84 | 90 | 92 | 92 | 87 | 78 | 68 | 60 | 77 |
| Avg low °F | 35 | 39 | 45 | 52 | 61 | 68 | 71 | 70 | 65 | 53 | 43 | 38 | 53 |
| Precip in | 4.9 | 5.1 | 5.5 | 4.5 | 4.0 | 4.9 | 4.6 | 4.3 | 3.5 | 2.8 | 3.7 | 4.9 | 52.7 |
1996–2025 normals for Marengo County — the climate division Demopolis sits in. All-time county record high 104.6°F (1952-07-25); record low 1.0°F (1985-01-21). Source: NOAA / National Weather Service.