The official National Weather Service forecast for Rensselaer — 40.9367°N, 87.1509°W, population 5,509, 3.9 miles from I-65. Forecasts here are written by NWS LOT, this county’s forecast office.
| Jasper County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 33 | 37 | 49 | 62 | 73 | 82 | 84 | 82 | 78 | 65 | 50 | 38 | 61 |
| Avg low °F | 17 | 20 | 29 | 38 | 50 | 59 | 62 | 60 | 53 | 42 | 32 | 23 | 40 |
| Precip in | 2.3 | 2.1 | 2.6 | 3.6 | 4.3 | 5.1 | 4.5 | 4.2 | 2.8 | 3.2 | 2.3 | 2.3 | 39.3 |
1996–2025 normals for Jasper County — the climate division Rensselaer sits in. All-time county record high 101.7°F (1988-08-18); record low -24.3°F (1985-01-20). Source: NOAA / National Weather Service.