The official National Weather Service forecast for Napoleon — 39.1314°N, 94.0708°W, 8.3 miles from I-70. Forecasts here are written by NWS EAX, this county’s forecast office.
| Lafayette County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 38 | 43 | 56 | 66 | 75 | 84 | 88 | 87 | 80 | 68 | 55 | 43 | 65 |
| Avg low °F | 20 | 24 | 34 | 44 | 54 | 64 | 68 | 65 | 57 | 45 | 35 | 25 | 45 |
| Precip in | 1.5 | 1.7 | 3.0 | 3.9 | 5.0 | 5.1 | 4.7 | 4.0 | 3.6 | 3.3 | 2.2 | 1.7 | 39.7 |
1996–2025 normals for Lafayette County — the climate division Napoleon sits in. All-time county record high 110.8°F (1954-07-14); record low -22.8°F (1989-12-23). Source: NOAA / National Weather Service.