Haileyville, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.2 °C (low) to 22.9 °C (high). Annual precipitation averages 1180.8 Millimeters. Haileyville 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 | -1.8 °C | 10.7 °C | 66.29 mm |
| February | 0.3 °C | 13.1 °C | 64.77 mm |
| March | 4.9 °C | 17.9 °C | 97.28 mm |
| April | 9.4 °C | 22.7 °C | 120.14 mm |
| May | 15 °C | 26.4 °C | 151.64 mm |
| June | 19.8 °C | 31.1 °C | 117.6 mm |
| July | 21.8 °C | 34.1 °C | 91.95 mm |
| August | 20.9 °C | 34.2 °C | 79.25 mm |
| September | 16.7 °C | 30.2 °C | 107.19 mm |
| October | 10.4 °C | 24.1 °C | 106.93 mm |
| November | 4.6 °C | 17.6 °C | 91.95 mm |
| December | -0.2 °C | 12.1 °C | 85.85 mm |
| Annual | 10.2 °C | 22.9 °C | 1180.84 mm |
| 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 : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |