Fountain Hills, Arizona has a Hot Desert Climate climate (Köppen classification: BWh). Average annual temperatures range from 15.1 °C (low) to 29.7 °C (high). Annual precipitation averages 254.3 Millimeters. Fountain Hills is located in USDA Plant Hardiness Zone 9b. The growing season typically runs from the last frost around Frost Rare through the first frost around Frost Rare.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 5.9 °C | 19.2 °C | 36.07 mm |
| February | 7.2 °C | 20.8 °C | 33.02 mm |
| March | 9.5 °C | 24.4 °C | 37.85 mm |
| April | 12.6 °C | 28.5 °C | 8.89 mm |
| May | 17.4 °C | 33.6 °C | 5.33 mm |
| June | 22.2 °C | 39 °C | 1.27 mm |
| July | 26 °C | 40.3 °C | 23.62 mm |
| August | 25.6 °C | 39.7 °C | 30.23 mm |
| September | 22.5 °C | 37.2 °C | 21.59 mm |
| October | 16.3 °C | 31.3 °C | 12.19 mm |
| November | 10.3 °C | 24.2 °C | 13.72 mm |
| December | 5.9 °C | 18.5 °C | 30.48 mm |
| Annual | 15.1 °C | 29.7 °C | 254.26 mm |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | Frost Rare |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9b : -3.9°C to -1.1°C |
| Plant Hardiness Zone - 2012 | Zone 9b : -3.9°C to -1.1°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BWh - Hot Desert Climate |