Denison, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 52.6 °F (low) to 73.8 °F (high). Annual precipitation averages 41.9 Inches. Denison is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 32.0 °F | 52.9 °F | 2.24 in. |
| February | 35.4 °F | 57.1 °F | 2.58 in. |
| March | 43.1 °F | 65.2 °F | 3.72 in. |
| April | 50.8 °F | 72.9 °F | 3.65 in. |
| May | 60.5 °F | 80.0 °F | 5.41 in. |
| June | 69.0 °F | 88.6 °F | 4.24 in. |
| July | 73.1 °F | 93.5 °F | 3.01 in. |
| August | 72.2 °F | 93.8 °F | 2.67 in. |
| September | 64.7 °F | 86.5 °F | 3.53 in. |
| October | 53.4 °F | 76.2 °F | 4.19 in. |
| November | 42.9 °F | 64.5 °F | 3.32 in. |
| December | 34.3 °F | 54.8 °F | 3.29 in. |
| Annual | 52.6 °F | 73.8 °F | 41.85 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8a : 10°F to 15°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |