The official National Weather Service forecast for Sigourney — 41.3333°N, 92.2046°W, 25.5 miles from I-80.
| Keokuk County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 31 | 36 | 49 | 62 | 72 | 82 | 85 | 83 | 78 | 65 | 50 | 36 | 61 |
| Avg low °F | 13 | 17 | 28 | 38 | 50 | 60 | 64 | 61 | 53 | 41 | 30 | 19 | 40 |
| Precip in | 1.3 | 1.4 | 2.2 | 3.6 | 5.0 | 5.1 | 4.0 | 3.9 | 3.0 | 3.1 | 1.9 | 1.7 | 36.2 |
1996–2025 normals for Keokuk County — the climate division Sigourney sits in. All-time county record high 105.7°F (2012-07-24); record low -26.9°F (2019-01-31). Source: NOAA / National Weather Service.