The official National Weather Service forecast for Napoleon — 46.5083°N, 99.7712°W, 26.5 miles from I-94.
| Logan County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 21 | 24 | 37 | 52 | 66 | 76 | 82 | 80 | 71 | 55 | 39 | 25 | 52 |
| Avg low °F | 3 | 5 | 17 | 28 | 41 | 52 | 58 | 55 | 46 | 33 | 20 | 8 | 30 |
| Precip in | 0.5 | 0.5 | 0.8 | 1.5 | 3.0 | 3.5 | 2.9 | 2.5 | 2.1 | 1.7 | 0.6 | 0.7 | 20.3 |
1996–2025 normals for Logan County — the climate division Napoleon sits in. All-time county record high 108.3°F (1973-07-12); record low -40.0°F (1951-01-29). Source: NOAA / National Weather Service.