De Kalb, Mississippi has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 52.1 °F (low) to 75.4 °F (high). Annual precipitation averages 57.6 Inches. De Kalb is located in USDA Plant Hardiness Zone 8b. 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 | 34.5 °F | 56.4 °F | 5.39 in. |
| February | 37.6 °F | 61.1 °F | 5.47 in. |
| March | 43.9 °F | 68.8 °F | 5.64 in. |
| April | 50.8 °F | 76.0 °F | 5.69 in. |
| May | 59.6 °F | 82.6 °F | 4.49 in. |
| June | 67.0 °F | 88.7 °F | 4.76 in. |
| July | 69.7 °F | 91.1 °F | 5.15 in. |
| August | 68.8 °F | 90.9 °F | 4.39 in. |
| September | 63.6 °F | 86.1 °F | 3.38 in. |
| October | 52.0 °F | 77.5 °F | 3.75 in. |
| November | 41.8 °F | 66.6 °F | 4.13 in. |
| December | 36.4 °F | 58.6 °F | 5.37 in. |
| Annual | 52.1 °F | 75.4 °F | 57.61 in. |
| 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 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 |