Rillito, Arizona has a Hot Semi-Arid Climate climate (Köppen classification: BSh). Average annual temperatures range from 55.6 °F (low) to 85 °F (high). Annual precipitation averages 11 Inches. Rillito is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 38.6 °F | 66.7 °F | 1.04 in. |
| February | 41.3 °F | 69.7 °F | 0.91 in. |
| March | 46.1 °F | 76.6 °F | 0.64 in. |
| April | 51.0 °F | 83.5 °F | 0.38 in. |
| May | 59.5 °F | 92.6 °F | 0.34 in. |
| June | 69.1 °F | 102.2 °F | 0.19 in. |
| July | 75.9 °F | 102.2 °F | 1.81 in. |
| August | 75.0 °F | 100.1 °F | 2.18 in. |
| September | 69.4 °F | 96.7 °F | 1.21 in. |
| October | 57.2 °F | 88.0 °F | 0.76 in. |
| November | 45.6 °F | 76.1 °F | 0.57 in. |
| December | 38.0 °F | 65.6 °F | 0.97 in. |
| Annual | 55.6 °F | 85 °F | 11 in. |
| Average First Frost Date | Jan. 21 - Jan. 31 |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9b : 25°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 9a : 20°F to 25°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | BSh - Hot Semi-Arid Climate |