Supai, Arizona has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 49.1 °F (low) to 77.7 °F (high). Annual precipitation averages 8.5 Inches. Supai is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 31.0 °F | 54.0 °F | 0.74 in. |
| February | 34.9 °F | 59.0 °F | 1.06 in. |
| March | 40.7 °F | 67.9 °F | 0.73 in. |
| April | 46.3 °F | 77.2 °F | 0.49 in. |
| May | 54.5 °F | 86.9 °F | 0.28 in. |
| June | 63.5 °F | 97.9 °F | 0.27 in. |
| July | 69.6 °F | 101.3 °F | 1.07 in. |
| August | 69.0 °F | 98.7 °F | 1.11 in. |
| September | 60.9 °F | 92.9 °F | 0.62 in. |
| October | 49.4 °F | 79.9 °F | 0.74 in. |
| November | 38.4 °F | 64.0 °F | 0.56 in. |
| December | 30.6 °F | 52.5 °F | 0.82 in. |
| Annual | 49.1 °F | 77.7 °F | 8.49 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |