The official National Weather Service forecast for Constantine — 41.8412°N, 85.6686°W, 6.3 miles from I-80. Forecasts here are written by NWS IWX, this county’s forecast office.
| St. Joseph County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 32 | 36 | 47 | 60 | 71 | 80 | 83 | 81 | 76 | 62 | 48 | 37 | 59 |
| Avg low °F | 18 | 19 | 28 | 37 | 48 | 58 | 61 | 60 | 53 | 42 | 32 | 23 | 40 |
| Precip in | 2.3 | 2.1 | 2.5 | 3.4 | 4.3 | 4.3 | 3.7 | 3.7 | 3.2 | 3.6 | 2.4 | 2.4 | 37.9 |
1996–2025 normals for St. Joseph County — the climate division Constantine sits in. All-time county record high 103.0°F (2012-07-07); record low -19.9°F (1994-01-19). Source: NOAA / National Weather Service.