The official National Weather Service forecast for Buchanan — 41.8273°N, 86.3611°W, population 5,640, 6.7 miles from I-80. Forecasts here are written by NWS IWX, this county’s forecast office.
| Berrien County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 33 | 36 | 47 | 59 | 70 | 79 | 83 | 81 | 76 | 63 | 49 | 38 | 60 |
| Avg low °F | 19 | 21 | 28 | 37 | 48 | 58 | 62 | 61 | 54 | 43 | 33 | 25 | 41 |
| Precip in | 2.5 | 2.2 | 2.5 | 3.5 | 4.1 | 4.0 | 3.6 | 3.9 | 3.0 | 4.0 | 2.5 | 2.6 | 38.4 |
1996–2025 normals for Berrien County — the climate division Buchanan sits in. All-time county record high 100.1°F (1999-07-31); record low -17.5°F (1994-01-19). Source: NOAA / National Weather Service.