Willow Valley, Arizona has a Hot Desert Climate climate (Köppen classification: BWh). Average annual temperatures range from 13.7 °C (low) to 30.4 °C (high). Annual precipitation averages 142.2 Millimeters. Willow Valley is located in USDA Plant Hardiness Zone 9a.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.6 °C | 18.9 °C | 22.86 mm |
| February | 5.8 °C | 21.3 °C | 25.65 mm |
| March | 8.7 °C | 25.7 °C | 20.07 mm |
| April | 11.7 °C | 29.3 °C | 5.59 mm |
| May | 16.7 °C | 34.6 °C | 1.78 mm |
| June | 20.8 °C | 39.4 °C | 0.51 mm |
| July | 25.6 °C | 41.9 °C | 8.64 mm |
| August | 24.9 °C | 41.6 °C | 12.95 mm |
| September | 20.6 °C | 38.3 °C | 12.19 mm |
| October | 13.7 °C | 31.4 °C | 9.4 mm |
| November | 7.3 °C | 24.1 °C | 7.87 mm |
| December | 4 °C | 18 °C | 14.73 mm |
| Annual | 13.7 °C | 30.4 °C | 142.24 mm |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 9b : -3.9°C to -1.1°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BWh - Hot Desert Climate |