Dumas, Texas has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 5.8 °C (low) to 21.6 °C (high). Annual precipitation averages 408 Millimeters. Dumas is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -5.6 °C | 9.9 °C | 10.16 mm |
| February | -4.2 °C | 12 °C | 8.64 mm |
| March | -0.3 °C | 16.9 °C | 22.61 mm |
| April | 4.1 °C | 21 °C | 30.23 mm |
| May | 10 °C | 26.3 °C | 45.21 mm |
| June | 15.6 °C | 31.6 °C | 58.93 mm |
| July | 18.2 °C | 33.6 °C | 67.31 mm |
| August | 17.4 °C | 32.5 °C | 63.25 mm |
| September | 13.1 °C | 28.4 °C | 30.23 mm |
| October | 6.1 °C | 22.2 °C | 42.42 mm |
| November | -0.5 °C | 15.4 °C | 12.45 mm |
| December | -4.9 °C | 9.9 °C | 16.51 mm |
| Annual | 5.8 °C | 21.6 °C | 407.95 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |