The official National Weather Service forecast for Union — 37.5915°N, 80.5437°W, 15.6 miles from I-64.
| Monroe County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 41 | 46 | 55 | 65 | 73 | 80 | 83 | 81 | 76 | 65 | 54 | 45 | 64 |
| Avg low °F | 23 | 26 | 32 | 41 | 49 | 57 | 61 | 60 | 53 | 42 | 32 | 27 | 42 |
| Precip in | 3.2 | 3.0 | 3.3 | 3.9 | 5.0 | 4.0 | 4.4 | 3.8 | 3.7 | 2.9 | 2.7 | 3.1 | 43.0 |
1996–2025 normals for Monroe County — the climate division Union sits in. All-time county record high 96.7°F (2012-06-30); record low -19.0°F (1985-01-21). Source: NOAA / National Weather Service.