Hallett, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 48.7 °F (low) to 71.7 °F (high). Annual precipitation averages 40.2 Inches. Hallett is located in USDA Plant Hardiness Zone 7a. 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 | 26.1 °F | 49.1 °F | 1.56 in. |
| February | 29.5 °F | 53.6 °F | 1.69 in. |
| March | 38.4 °F | 62.9 °F | 3.07 in. |
| April | 47.7 °F | 72.5 °F | 4.26 in. |
| May | 57.9 °F | 79.3 °F | 5.81 in. |
| June | 66.8 °F | 87.3 °F | 4.6 in. |
| July | 71.0 °F | 92.5 °F | 3.79 in. |
| August | 69.5 °F | 92.6 °F | 3.62 in. |
| September | 61.1 °F | 84.6 °F | 3.82 in. |
| October | 49.3 °F | 74.0 °F | 3.67 in. |
| November | 37.8 °F | 61.9 °F | 2.38 in. |
| December | 29.0 °F | 50.6 °F | 1.88 in. |
| Annual | 48.7 °F | 71.7 °F | 40.15 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 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |