O'Donnell, Texas has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 47.3 °F (low) to 75.1 °F (high). Annual precipitation averages 18.9 Inches. O'Donnell is located in USDA Plant Hardiness Zone 8a. 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 | 27.2 °F | 55.4 °F | 0.7 in. |
| February | 30.2 °F | 59.9 °F | 0.74 in. |
| March | 37.5 °F | 68.0 °F | 1.08 in. |
| April | 45.4 °F | 76.2 °F | 1.24 in. |
| May | 55.7 °F | 84.0 °F | 2.62 in. |
| June | 64.7 °F | 90.9 °F | 2.52 in. |
| July | 67.8 °F | 92.9 °F | 1.91 in. |
| August | 66.6 °F | 92.0 °F | 1.94 in. |
| September | 59.6 °F | 84.4 °F | 2.74 in. |
| October | 48.3 °F | 76.3 °F | 1.57 in. |
| November | 36.2 °F | 64.4 °F | 1.01 in. |
| December | 28.9 °F | 56.3 °F | 0.78 in. |
| Annual | 47.3 °F | 75.1 °F | 18.85 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 8a : 10°F to 15°F |
| Plant Hardiness Zone - 2012 | Zone 7b : 5°F to 10°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |