Allen, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 49.4 °F (low) to 72.9 °F (high). Annual precipitation averages 42.1 Inches. Allen 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 | 27.9 °F | 51.3 °F | 1.97 in. |
| February | 31.4 °F | 55.3 °F | 2.1 in. |
| March | 39.9 °F | 64.0 °F | 3.27 in. |
| April | 48.1 °F | 72.6 °F | 4.21 in. |
| May | 58.1 °F | 79.4 °F | 5.55 in. |
| June | 66.9 °F | 87.7 °F | 4.78 in. |
| July | 70.6 °F | 93.1 °F | 3.68 in. |
| August | 69.2 °F | 93.5 °F | 3.04 in. |
| September | 61.4 °F | 86.1 °F | 4.08 in. |
| October | 49.9 °F | 74.9 °F | 3.92 in. |
| November | 39.2 °F | 63.5 °F | 2.85 in. |
| December | 30.4 °F | 53.0 °F | 2.69 in. |
| Annual | 49.4 °F | 72.9 °F | 42.14 in. |
| 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 : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7b : 5°F to 10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |