The official National Weather Service forecast for Chatham — 46.3477°N, 86.929°W, 107.5 miles from I-75. Forecasts here are written by NWS MQT, this county’s forecast office.
| Alger County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 25 | 27 | 36 | 48 | 62 | 72 | 77 | 75 | 68 | 54 | 41 | 30 | 51 |
| Avg low °F | 10 | 10 | 17 | 28 | 39 | 49 | 54 | 54 | 48 | 38 | 27 | 17 | 33 |
| Precip in | 2.6 | 1.9 | 2.0 | 2.9 | 3.1 | 3.5 | 3.4 | 3.0 | 3.6 | 3.9 | 3.1 | 2.7 | 35.7 |
1996–2025 normals for Alger County — the climate division Chatham sits in. All-time county record high 95.9°F (2026-07-15); record low -28.9°F (1979-02-18). Source: NOAA / National Weather Service.