The official National Weather Service forecast for Alamo — 39.982°N, 87.0572°W, 9 miles from I-74. Forecasts here are written by NWS IND, this county’s forecast office.
| Montgomery 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 | 78 | 66 | 51 | 39 | 62 |
| Avg low °F | 18 | 21 | 31 | 40 | 51 | 60 | 63 | 61 | 54 | 43 | 33 | 24 | 42 |
| Precip in | 2.7 | 2.4 | 3.2 | 4.2 | 4.6 | 4.9 | 4.4 | 3.4 | 2.9 | 3.4 | 2.8 | 3.0 | 41.9 |
1996–2025 normals for Montgomery County — the climate division Alamo sits in. All-time county record high 102.8°F (1954-07-15); record low -25.2°F (1994-01-19). Source: NOAA / National Weather Service.