Westport, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.3 °C (low) to 22.1 °C (high). Annual precipitation averages 1038.1 Millimeters. Westport is located in USDA Plant Hardiness Zone 7b. 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 | -3.2 °C | 9.6 °C | 40.89 mm |
| February | -1.3 °C | 12.1 °C | 44.45 mm |
| March | 3.6 °C | 17.3 °C | 77.72 mm |
| April | 8.8 °C | 22.4 °C | 115.32 mm |
| May | 14.3 °C | 26.2 °C | 145.03 mm |
| June | 19.3 °C | 30.8 °C | 121.92 mm |
| July | 21.6 °C | 33.8 °C | 96.77 mm |
| August | 20.7 °C | 33.8 °C | 93.22 mm |
| September | 16 °C | 29.2 °C | 96.27 mm |
| October | 9.5 °C | 23.4 °C | 89.92 mm |
| November | 3.3 °C | 16.6 °C | 64.52 mm |
| December | -1.6 °C | 10.4 °C | 52.07 mm |
| Annual | 9.3 °C | 22.1 °C | 1038.1 mm |
| 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 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |