The official National Weather Service forecast for State Line — 40.1973°N, 87.527°W, 5.5 miles from I-74. Forecasts here are written by NWS IND, this county’s forecast office.
| Warren County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 34 | 39 | 51 | 63 | 74 | 82 | 84 | 83 | 79 | 66 | 51 | 39 | 62 |
| Avg low °F | 18 | 21 | 30 | 40 | 51 | 60 | 63 | 61 | 54 | 43 | 32 | 23 | 41 |
| Precip in | 2.4 | 2.1 | 2.8 | 3.8 | 4.4 | 4.8 | 4.3 | 3.6 | 2.8 | 3.2 | 2.6 | 2.5 | 39.3 |
1996–2025 normals for Warren County — the climate division State Line sits in. All-time county record high 102.1°F (2012-07-08); record low -24.3°F (1985-01-20). Source: NOAA / National Weather Service.