First Mesa, Arizona has a Cold Desert Climate climate (Köppen classification: BWk). Average annual temperatures range from 37.9 °F (low) to 69 °F (high). Annual precipitation averages 8.5 Inches. First Mesa is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.0 °F | 46.7 °F | 0.85 in. |
| February | 23.5 °F | 51.5 °F | 0.64 in. |
| March | 28.5 °F | 59.8 °F | 0.68 in. |
| April | 34.6 °F | 67.0 °F | 0.45 in. |
| May | 42.8 °F | 76.6 °F | 0.35 in. |
| June | 51.3 °F | 88.3 °F | 0.11 in. |
| July | 59.5 °F | 91.6 °F | 1.02 in. |
| August | 58.8 °F | 88.9 °F | 1.22 in. |
| September | 50.3 °F | 82.4 °F | 0.94 in. |
| October | 38.4 °F | 70.9 °F | 0.8 in. |
| November | 27.3 °F | 57.8 °F | 0.56 in. |
| December | 19.3 °F | 46.6 °F | 0.85 in. |
| Annual | 37.9 °F | 69 °F | 8.47 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BWk - Cold Desert Climate |