The official National Weather Service forecast for Harrisburg — 41.5564°N, 103.7386°W, 24 miles from I-80.
| Banner County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 40 | 42 | 52 | 60 | 68 | 81 | 89 | 86 | 78 | 63 | 51 | 41 | 63 |
| Avg low °F | 16 | 17 | 24 | 31 | 41 | 51 | 58 | 55 | 46 | 33 | 23 | 17 | 34 |
| Precip in | 0.4 | 0.6 | 1.2 | 1.9 | 3.2 | 2.3 | 2.1 | 1.8 | 1.5 | 1.3 | 0.6 | 0.5 | 17.4 |
1996–2025 normals for Banner County — the climate division Harrisburg sits in. All-time county record high 104.9°F (2012-06-26); record low -35.7°F (1989-12-22). Source: NOAA / National Weather Service.