The official National Weather Service forecast for Corunna — 42.982°N, 84.1178°W, 7.2 miles from I-69. Forecasts here are written by NWS DTX, this county’s forecast office.
| Shiawassee County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 30 | 34 | 45 | 58 | 69 | 79 | 83 | 80 | 74 | 61 | 47 | 36 | 58 |
| Avg low °F | 17 | 18 | 26 | 36 | 47 | 57 | 60 | 59 | 52 | 41 | 31 | 23 | 39 |
| Precip in | 2.1 | 1.9 | 2.2 | 3.1 | 4.0 | 3.6 | 3.2 | 3.4 | 2.8 | 3.2 | 2.2 | 2.1 | 33.8 |
1996–2025 normals for Shiawassee County — the climate division Corunna sits in. All-time county record high 101.1°F (1988-07-07); record low -19.7°F (1994-01-19). Source: NOAA / National Weather Service.