Supai, Arizona has a Hot-Summer Mediterranean Climate climate (Köppen classification: Csa). Average annual temperatures range from 9.5 °C (low) to 25.4 °C (high). Annual precipitation averages 215.7 Millimeters. 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 | -0.6 °C | 12.2 °C | 18.8 mm |
| February | 1.6 °C | 15 °C | 26.92 mm |
| March | 4.8 °C | 19.9 °C | 18.54 mm |
| April | 7.9 °C | 25.1 °C | 12.45 mm |
| May | 12.5 °C | 30.5 °C | 7.11 mm |
| June | 17.5 °C | 36.6 °C | 6.86 mm |
| July | 20.9 °C | 38.5 °C | 27.18 mm |
| August | 20.6 °C | 37.1 °C | 28.19 mm |
| September | 16.1 °C | 33.8 °C | 15.75 mm |
| October | 9.7 °C | 26.6 °C | 18.8 mm |
| November | 3.6 °C | 17.8 °C | 14.22 mm |
| December | -0.8 °C | 11.4 °C | 20.83 mm |
| Annual | 9.5 °C | 25.4 °C | 215.65 mm |
| 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 : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Csa - Hot-Summer Mediterranean Climate |