Boswell, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 10.5 °C (low) to 23.5 °C (high). Annual precipitation averages 1154.4 Millimeters. Boswell 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 | -1.2 °C | 11.6 °C | 65.28 mm |
| February | 1.1 °C | 14.2 °C | 74.17 mm |
| March | 5.4 °C | 18.6 °C | 102.87 mm |
| April | 9.7 °C | 23.1 °C | 108.46 mm |
| May | 15.2 °C | 27 °C | 155.7 mm |
| June | 19.9 °C | 31.6 °C | 112.27 mm |
| July | 21.7 °C | 34.3 °C | 76.2 mm |
| August | 21.1 °C | 34.6 °C | 73.91 mm |
| September | 17.1 °C | 30.8 °C | 91.69 mm |
| October | 10.4 °C | 24.7 °C | 115.32 mm |
| November | 4.7 °C | 18.2 °C | 91.19 mm |
| December | 0.4 °C | 12.8 °C | 87.38 mm |
| Annual | 10.5 °C | 23.5 °C | 1154.44 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 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |