The official National Weather Service forecast for Alcester — 43.0214°N, 96.6309°W, 9.4 miles from I-29.
| Union County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 28 | 33 | 47 | 60 | 72 | 82 | 86 | 83 | 77 | 63 | 47 | 32 | 59 |
| Avg low °F | 10 | 13 | 25 | 36 | 48 | 59 | 63 | 61 | 52 | 39 | 26 | 15 | 37 |
| Precip in | 0.7 | 0.7 | 1.5 | 2.8 | 3.9 | 4.4 | 3.2 | 3.3 | 2.8 | 2.3 | 1.2 | 1.0 | 27.8 |
1996–2025 normals for Union County — the climate division Alcester sits in. All-time county record high 106.5°F (1988-06-22); record low -29.2°F (1970-01-19). Source: NOAA / National Weather Service.