The official National Weather Service forecast for Denison — 42.0178°N, 95.3553°W, population 8,142, 37.4 miles from I-80.
| Crawford County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 29 | 33 | 47 | 61 | 71 | 82 | 84 | 82 | 77 | 63 | 48 | 34 | 59 |
| Avg low °F | 11 | 14 | 27 | 37 | 48 | 59 | 63 | 60 | 52 | 40 | 27 | 16 | 38 |
| Precip in | 0.8 | 1.0 | 1.9 | 3.2 | 4.8 | 4.8 | 3.8 | 4.3 | 2.9 | 2.5 | 1.4 | 1.2 | 32.6 |
1996–2025 normals for Crawford County — the climate division Denison sits in. All-time county record high 104.0°F (1955-07-31); record low -26.9°F (2021-02-16). Source: NOAA / National Weather Service.