The official National Weather Service forecast for Gretna — 41.1408°N, 96.2397°W, 3.7 miles from I-80.
| Sarpy County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 33 | 38 | 52 | 64 | 74 | 84 | 87 | 85 | 79 | 66 | 51 | 38 | 63 |
| Avg low °F | 15 | 18 | 29 | 40 | 51 | 62 | 66 | 64 | 55 | 42 | 30 | 19 | 41 |
| Precip in | 0.8 | 1.0 | 1.9 | 3.0 | 5.0 | 4.7 | 3.4 | 3.9 | 2.8 | 2.6 | 1.3 | 1.2 | 31.6 |
1996–2025 normals for Sarpy County — the climate division Gretna sits in. All-time county record high 105.7°F (1995-07-13); record low -26.1°F (1974-01-12). Source: NOAA / National Weather Service.