Olney, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 51.6 °F (low) to 77.1 °F (high). Annual precipitation averages 30.7 Inches. Olney 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. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 30.6 °F | 56.2 °F | 1.4 in. |
| February | 33.8 °F | 59.8 °F | 1.64 in. |
| March | 42.0 °F | 68.7 °F | 2.35 in. |
| April | 49.6 °F | 77.3 °F | 2.54 in. |
| May | 59.9 °F | 84.5 °F | 4.79 in. |
| June | 68.9 °F | 92.0 °F | 3.66 in. |
| July | 72.6 °F | 97.0 °F | 2.6 in. |
| August | 71.7 °F | 97.0 °F | 2.03 in. |
| September | 64.1 °F | 89.3 °F | 2.98 in. |
| October | 52.8 °F | 79.0 °F | 3.23 in. |
| November | 41.1 °F | 66.5 °F | 1.89 in. |
| December | 32.5 °F | 57.4 °F | 1.61 in. |
| Annual | 51.6 °F | 77.1 °F | 30.72 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : 10°F to 15°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |