The official National Weather Service forecast for Marion — 40.6775°N, 111.281°W, 11 miles from I-80. Forecasts here are written by NWS SLC, this county’s forecast office.
| Summit County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 32 | 34 | 42 | 48 | 57 | 67 | 76 | 73 | 65 | 52 | 41 | 32 | 52 |
| Avg low °F | 12 | 12 | 18 | 24 | 32 | 40 | 48 | 46 | 39 | 29 | 19 | 12 | 28 |
| Precip in | 2.6 | 2.4 | 2.7 | 2.7 | 2.3 | 1.4 | 1.1 | 1.7 | 1.9 | 2.2 | 2.2 | 2.7 | 25.9 |
1996–2025 normals for Summit County — the climate division Marion sits in. All-time county record high 89.2°F (2002-07-14); record low -35.2°F (1982-02-06). Source: NOAA / National Weather Service.