Dumas, Mississippi has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.6 °C (low) to 21.8 °C (high). Annual precipitation averages 1471.9 Millimeters. Dumas is located in USDA Plant Hardiness Zone 7b. 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 | -1.2 °C | 9.9 °C | 124.97 mm |
| February | 0.3 °C | 12.4 °C | 128.27 mm |
| March | 4.4 °C | 17.4 °C | 136.65 mm |
| April | 9 °C | 22.3 °C | 143 mm |
| May | 14.3 °C | 26.4 °C | 135.38 mm |
| June | 18.7 °C | 30.2 °C | 121.92 mm |
| July | 20.6 °C | 31.9 °C | 116.33 mm |
| August | 19.8 °C | 31.7 °C | 96.01 mm |
| September | 15.9 °C | 28.8 °C | 102.11 mm |
| October | 9.2 °C | 22.9 °C | 99.82 mm |
| November | 3.5 °C | 16.5 °C | 110.24 mm |
| December | 0.5 °C | 11.4 °C | 157.23 mm |
| Annual | 9.6 °C | 21.8 °C | 1471.93 mm |
| 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 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |