The official National Weather Service forecast for Dayton — 35.494°N, 85.0125°W, population 9,688, 17.2 miles from I-75.
| Rhea County | J | F | M | A | M | J | J | A | S | O | N | D | Year |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Avg high °F | 47 | 52 | 61 | 70 | 77 | 84 | 87 | 86 | 81 | 71 | 60 | 51 | 69 |
| Avg low °F | 29 | 32 | 39 | 46 | 56 | 63 | 67 | 66 | 59 | 48 | 38 | 32 | 48 |
| Precip in | 5.1 | 5.5 | 5.5 | 5.2 | 4.7 | 4.8 | 5.0 | 3.8 | 4.5 | 3.4 | 4.5 | 6.2 | 58.2 |
1996–2025 normals for Rhea County — the climate division Dayton sits in. All-time county record high 104.2°F (1980-07-17); record low -16.0°F (1985-01-21). Source: NOAA / National Weather Service.