Ajo, Arizona has a Hot Desert Climate climate (Köppen classification: BWh). Average annual temperatures range from 61.2 °F (low) to 84.5 °F (high). Annual precipitation averages 7.1 Inches. Ajo is located in USDA Plant Hardiness Zone 10a.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 44.5 °F | 66.0 °F | 0.47 in. |
| February | 47.8 °F | 69.3 °F | 0.72 in. |
| March | 52.3 °F | 75.8 °F | 0.69 in. |
| April | 57.7 °F | 82.5 °F | 0.16 in. |
| May | 65.6 °F | 90.2 °F | 0.1 in. |
| June | 74.4 °F | 100.2 °F | 0.06 in. |
| July | 79.2 °F | 102.4 °F | 0.84 in. |
| August | 79.8 °F | 101.8 °F | 1.74 in. |
| September | 74.0 °F | 97.7 °F | 0.7 in. |
| October | 63.4 °F | 87.6 °F | 0.45 in. |
| November | 52.1 °F | 75.6 °F | 0.46 in. |
| December | 43.8 °F | 65.2 °F | 0.74 in. |
| Annual | 61.2 °F | 84.5 °F | 7.13 in. |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | |
| Average Days With Frost | Frost Free |
| Plant Hardiness Zone | Zone 10a : 30°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 10a : 30°F to 25°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BWh - Hot Desert Climate |