Dennis, Mississippi has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 49.4 °F (low) to 71.9 °F (high). Annual precipitation averages 60.1 Inches. Dennis is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 29.7 °F | 50.3 °F | 5.3 in. |
| February | 32.9 °F | 55.2 °F | 5.45 in. |
| March | 40.0 °F | 63.8 °F | 5.6 in. |
| April | 48.6 °F | 73.1 °F | 5.45 in. |
| May | 57.8 °F | 80.4 °F | 5.83 in. |
| June | 65.8 °F | 86.6 °F | 4.47 in. |
| July | 68.7 °F | 89.5 °F | 4.81 in. |
| August | 68.2 °F | 89.8 °F | 4.43 in. |
| September | 61.0 °F | 84.4 °F | 4.13 in. |
| October | 49.1 °F | 74.0 °F | 3.86 in. |
| November | 38.4 °F | 62.3 °F | 4.44 in. |
| December | 32.9 °F | 53.1 °F | 6.31 in. |
| Annual | 49.4 °F | 71.9 °F | 60.08 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7b : 5°F to 10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |