The official National Weather Service forecast for Portage — 42.2011°N, 85.58°W, 2.5 miles from I-94. Forecasts here are written by NWS GRR, this county’s forecast office.
| Kalamazoo County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 31 | 35 | 46 | 59 | 70 | 80 | 83 | 81 | 75 | 62 | 48 | 37 | 59 |
| Avg low °F | 18 | 19 | 27 | 37 | 48 | 58 | 61 | 59 | 52 | 42 | 32 | 23 | 40 |
| Precip in | 2.3 | 2.0 | 2.4 | 3.3 | 4.3 | 4.2 | 3.6 | 3.6 | 3.1 | 3.8 | 2.3 | 2.4 | 37.3 |
1996–2025 normals for Kalamazoo County — the climate division Portage sits in. All-time county record high 102.9°F (2012-07-07); record low -18.5°F (1994-01-19). Source: NOAA / National Weather Service.