The official National Weather Service forecast for O'Neill — 42.4578°N, 98.6476°W, 97 miles from I-29.
| Holt County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 33 | 36 | 49 | 60 | 70 | 81 | 87 | 84 | 78 | 63 | 49 | 36 | 60 |
| Avg low °F | 12 | 15 | 25 | 34 | 46 | 57 | 62 | 60 | 51 | 37 | 25 | 15 | 37 |
| Precip in | 0.5 | 0.7 | 1.3 | 2.8 | 3.9 | 3.9 | 3.0 | 3.0 | 2.3 | 2.2 | 0.8 | 0.7 | 25.1 |
1996–2025 normals for Holt County — the climate division O'Neill sits in. All-time county record high 105.7°F (2012-08-30); record low -30.1°F (1989-12-22). Source: NOAA / National Weather Service.