Altha, Florida has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 13.3 °C (low) to 25.9 °C (high). Annual precipitation averages 1492.3 Millimeters. Altha is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.1 °C | 16.9 °C | 122.43 mm |
| February | 5.7 °C | 19 °C | 118.36 mm |
| March | 8.5 °C | 22.8 °C | 132.59 mm |
| April | 12.2 °C | 26.2 °C | 116.33 mm |
| May | 17.2 °C | 30.2 °C | 94.49 mm |
| June | 20.8 °C | 32.3 °C | 156.21 mm |
| July | 21.9 °C | 33.2 °C | 164.34 mm |
| August | 21.7 °C | 32.5 °C | 155.7 mm |
| September | 19.6 °C | 30.8 °C | 151.38 mm |
| October | 14.2 °C | 27.1 °C | 81.28 mm |
| November | 8.1 °C | 21.8 °C | 91.95 mm |
| December | 5.7 °C | 18.2 °C | 107.19 mm |
| Annual | 13.3 °C | 25.9 °C | 1492.25 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |