The official National Weather Service forecast for Cottage Grove — 36.3792°N, 88.4792°W, 40.5 miles from I-40.
| Henry County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 47 | 51 | 61 | 71 | 79 | 86 | 89 | 88 | 83 | 72 | 60 | 50 | 70 |
| Avg low °F | 28 | 32 | 39 | 47 | 57 | 65 | 69 | 67 | 60 | 48 | 38 | 32 | 48 |
| Precip in | 4.4 | 4.7 | 5.2 | 5.4 | 5.6 | 4.4 | 4.2 | 3.5 | 3.5 | 3.5 | 4.1 | 5.0 | 53.5 |
1996–2025 normals for Henry County — the climate division Cottage Grove sits in. All-time county record high 105.6°F (2012-06-30); record low -18.4°F (1951-02-02). Source: NOAA / National Weather Service.