The official National Weather Service forecast for Valparaiso — 41.4731°N, 87.0611°W, population 51,867, 7.7 miles from I-90. Forecasts here are written by NWS LOT, this county’s forecast office.
| Porter County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 32 | 36 | 48 | 60 | 71 | 80 | 83 | 81 | 77 | 64 | 49 | 37 | 60 |
| Avg low °F | 17 | 20 | 29 | 38 | 49 | 59 | 63 | 61 | 54 | 43 | 32 | 23 | 41 |
| Precip in | 2.2 | 2.1 | 2.6 | 3.5 | 4.5 | 4.3 | 4.1 | 4.3 | 3.0 | 3.6 | 2.3 | 2.4 | 38.9 |
1996–2025 normals for Porter County — the climate division Valparaiso sits in. All-time county record high 100.7°F (1953-09-02); record low -21.6°F (1985-01-20). Source: NOAA / National Weather Service.