The official National Weather Service forecast for Norwalk — 41.4755°N, 93.6788°W, 5.8 miles from I-35.
| Warren County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 32 | 36 | 50 | 62 | 72 | 82 | 86 | 84 | 78 | 65 | 50 | 37 | 61 |
| Avg low °F | 14 | 17 | 29 | 40 | 50 | 61 | 65 | 62 | 54 | 42 | 30 | 19 | 40 |
| Precip in | 1.0 | 1.2 | 2.0 | 3.5 | 5.2 | 5.2 | 4.2 | 4.1 | 3.2 | 2.9 | 1.7 | 1.4 | 35.6 |
1996–2025 normals for Warren County — the climate division Norwalk sits in. All-time county record high 105.0°F (1983-08-17); record low -28.6°F (1996-02-03). Source: NOAA / National Weather Service.