Ajo, Arizona has a Hot Desert Climate climate (Köppen classification: BWh). Average annual temperatures range from 16.2 °C (low) to 29.2 °C (high). Annual precipitation averages 181.1 Millimeters. Ajo is located in USDA Plant Hardiness Zone 10a.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.9 °C | 18.9 °C | 11.94 mm |
| February | 8.8 °C | 20.7 °C | 18.29 mm |
| March | 11.3 °C | 24.3 °C | 17.53 mm |
| April | 14.3 °C | 28.1 °C | 4.06 mm |
| May | 18.7 °C | 32.3 °C | 2.54 mm |
| June | 23.6 °C | 37.9 °C | 1.52 mm |
| July | 26.2 °C | 39.1 °C | 21.34 mm |
| August | 26.6 °C | 38.8 °C | 44.2 mm |
| September | 23.3 °C | 36.5 °C | 17.78 mm |
| October | 17.4 °C | 30.9 °C | 11.43 mm |
| November | 11.2 °C | 24.2 °C | 11.68 mm |
| December | 6.6 °C | 18.4 °C | 18.8 mm |
| Annual | 16.2 °C | 29.2 °C | 181.11 mm |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | |
| Average Days With Frost | Frost Free |
| Plant Hardiness Zone | Zone 10a : -1.1°C to 1.7°C |
| Plant Hardiness Zone - 2012 | Zone 10a : -1.1°C to 1.7°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BWh - Hot Desert Climate |