The official National Weather Service forecast for Grand Marais — 47.7505°N, 90.3343°W, 103.9 miles from I-35. Forecasts here are written by NWS DLH, this county’s forecast office.
| Cook County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 18 | 22 | 34 | 46 | 60 | 69 | 75 | 73 | 65 | 50 | 35 | 22 | 47 |
| Avg low °F | -1 | 0 | 11 | 25 | 36 | 46 | 52 | 50 | 44 | 33 | 20 | 7 | 27 |
| Precip in | 1.3 | 1.3 | 1.5 | 2.7 | 3.1 | 4.1 | 3.5 | 2.8 | 3.2 | 3.1 | 2.1 | 2.0 | 30.7 |
1996–2025 normals for Cook County — the climate division Grand Marais sits in. All-time county record high 97.0°F (1976-08-20); record low -44.2°F (1972-01-16). Source: NOAA / National Weather Service.