The official National Weather Service forecast for Balfour — 47.9517°N, 100.5346°W, 76.8 miles from I-94.
| McHenry County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 19 | 22 | 35 | 52 | 66 | 76 | 82 | 81 | 72 | 55 | 37 | 23 | 52 |
| Avg low °F | 0 | 3 | 15 | 28 | 41 | 52 | 57 | 54 | 45 | 32 | 18 | 6 | 29 |
| Precip in | 0.4 | 0.4 | 0.6 | 1.1 | 2.6 | 3.6 | 2.6 | 2.1 | 1.7 | 1.3 | 0.6 | 0.6 | 17.6 |
1996–2025 normals for McHenry County — the climate division Balfour sits in. All-time county record high 104.4°F (1988-07-28); record low -39.0°F (1996-02-01). Source: NOAA / National Weather Service.