Alamo, Tennessee has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.8 °C (low) to 21.1 °C (high). Annual precipitation averages 1365.5 Millimeters. Alamo is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -1.7 °C | 8.3 °C | 101.85 mm |
| February | 0.1 °C | 10.9 °C | 115.06 mm |
| March | 4.3 °C | 15.9 °C | 132.84 mm |
| April | 9.4 °C | 21.5 °C | 128.52 mm |
| May | 15.1 °C | 26 °C | 145.29 mm |
| June | 19.4 °C | 30.2 °C | 101.35 mm |
| July | 21.2 °C | 31.8 °C | 99.06 mm |
| August | 20 °C | 31.4 °C | 91.19 mm |
| September | 15.9 °C | 28.3 °C | 96.77 mm |
| October | 9.3 °C | 22.6 °C | 99.82 mm |
| November | 3.9 °C | 15.7 °C | 116.59 mm |
| December | 0.1 °C | 10.1 °C | 137.16 mm |
| Annual | 9.8 °C | 21.1 °C | 1365.5 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |