Alva, Oklahoma has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 7.6 °C (low) to 22.2 °C (high). Annual precipitation averages 755.6 Millimeters. Alva 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 | -5.4 °C | 9 °C | 20.57 mm |
| February | -3.7 °C | 11.1 °C | 28.19 mm |
| March | 1.4 °C | 16.7 °C | 59.18 mm |
| April | 6.2 °C | 21.8 °C | 69.6 mm |
| May | 12.7 °C | 26.9 °C | 110.74 mm |
| June | 18.4 °C | 32.6 °C | 109.47 mm |
| July | 21 °C | 35.4 °C | 84.07 mm |
| August | 20.1 °C | 34.4 °C | 93.47 mm |
| September | 15.4 °C | 30.2 °C | 52.07 mm |
| October | 7.8 °C | 23.4 °C | 64.26 mm |
| November | 1.1 °C | 15.8 °C | 33.78 mm |
| December | -4.3 °C | 9.4 °C | 30.23 mm |
| Annual | 7.6 °C | 22.2 °C | 755.63 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |