The official National Weather Service forecast for Vermillion — 42.7794°N, 96.9292°W, population 11,659, 6.8 miles from I-29.
| Clay County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 29 | 33 | 47 | 60 | 71 | 82 | 86 | 83 | 77 | 63 | 47 | 33 | 59 |
| Avg low °F | 10 | 13 | 25 | 36 | 48 | 59 | 63 | 61 | 52 | 39 | 25 | 15 | 37 |
| Precip in | 0.6 | 0.7 | 1.5 | 2.9 | 3.7 | 4.2 | 3.0 | 3.3 | 2.8 | 2.3 | 1.1 | 0.9 | 27.0 |
1996–2025 normals for Clay County — the climate division Vermillion sits in. All-time county record high 107.3°F (1988-06-22); record low -31.4°F (1970-01-19). Source: NOAA / National Weather Service.