Forney, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 54.5 °F (low) to 75.9 °F (high). Annual precipitation averages 43.3 Inches. Forney is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 34.8 °F | 55.8 °F | 2.91 in. |
| February | 38.4 °F | 59.9 °F | 3.14 in. |
| March | 45.7 °F | 67.2 °F | 3.87 in. |
| April | 53.1 °F | 74.8 °F | 4.22 in. |
| May | 62.7 °F | 82.3 °F | 5.01 in. |
| June | 70.6 °F | 90.4 °F | 4.04 in. |
| July | 73.4 °F | 94.4 °F | 2.11 in. |
| August | 73.0 °F | 95.0 °F | 2.48 in. |
| September | 66.4 °F | 88.6 °F | 3.22 in. |
| October | 54.9 °F | 78.3 °F | 5.23 in. |
| November | 44.7 °F | 66.8 °F | 3.41 in. |
| December | 36.8 °F | 57.8 °F | 3.66 in. |
| Annual | 54.5 °F | 75.9 °F | 43.3 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 30-40 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |