San Tan Valley, Arizona has a Hot Semi-Arid Climate climate (Köppen classification: BSh). Average annual temperatures range from 58.2 °F (low) to 85.7 °F (high). Annual precipitation averages 8.8 Inches. San Tan Valley is located in USDA Plant Hardiness Zone 9b. The growing season typically runs from the last frost around Feb. 1 - Feb. 10 through the first frost around Dec. 11 - Dec. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 41.3 °F | 66.7 °F | 1.3 in. |
| February | 43.6 °F | 69.9 °F | 1.04 in. |
| March | 47.9 °F | 76.4 °F | 1.17 in. |
| April | 53.5 °F | 83.7 °F | 0.33 in. |
| May | 62.5 °F | 93.0 °F | 0.18 in. |
| June | 71.5 °F | 102.4 °F | 0.05 in. |
| July | 78.3 °F | 104.1 °F | 0.77 in. |
| August | 77.8 °F | 103.0 °F | 0.98 in. |
| September | 72.1 °F | 98.7 °F | 0.61 in. |
| October | 60.0 °F | 88.3 °F | 0.43 in. |
| November | 48.7 °F | 75.9 °F | 0.62 in. |
| December | 41.4 °F | 65.7 °F | 1.29 in. |
| Annual | 58.2 °F | 85.7 °F | 8.77 in. |
| Average First Frost Date | Dec. 11 - Dec. 20 |
| Average Last Frost Date | Feb. 1 - Feb. 10 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9b : 25°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 9b : 25°F to 20°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSh - Hot Semi-Arid Climate |