Altamont, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.1 °C (low) to 19.1 °C (high). Annual precipitation averages 1534.4 Millimeters. Altamont is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.2 °C | 7.5 °C | 135.38 mm |
| February | -1.6 °C | 9.7 °C | 136.65 mm |
| March | 2 °C | 14.3 °C | 150.11 mm |
| April | 6.4 °C | 19.5 °C | 158.5 mm |
| May | 11.4 °C | 23.5 °C | 120.14 mm |
| June | 15.6 °C | 27.1 °C | 124.46 mm |
| July | 17.6 °C | 28.8 °C | 126.49 mm |
| August | 16.8 °C | 28.7 °C | 108.97 mm |
| September | 13.3 °C | 26.1 °C | 99.31 mm |
| October | 6.8 °C | 20.4 °C | 86.61 mm |
| November | 1.7 °C | 14.3 °C | 118.36 mm |
| December | -1.4 °C | 9.2 °C | 169.42 mm |
| Annual | 7.1 °C | 19.1 °C | 1534.4 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |