First Mesa, Arizona has a Cold Desert Climate climate (Köppen classification: BWk). Average annual temperatures range from 3.3 °C (low) to 20.6 °C (high). Annual precipitation averages 215.1 Millimeters. 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 | -6.7 °C | 8.2 °C | 21.59 mm |
| February | -4.7 °C | 10.8 °C | 16.26 mm |
| March | -1.9 °C | 15.4 °C | 17.27 mm |
| April | 1.4 °C | 19.4 °C | 11.43 mm |
| May | 6 °C | 24.8 °C | 8.89 mm |
| June | 10.7 °C | 31.3 °C | 2.79 mm |
| July | 15.3 °C | 33.1 °C | 25.91 mm |
| August | 14.9 °C | 31.6 °C | 30.99 mm |
| September | 10.2 °C | 28 °C | 23.88 mm |
| October | 3.6 °C | 21.6 °C | 20.32 mm |
| November | -2.6 °C | 14.3 °C | 14.22 mm |
| December | -7.1 °C | 8.1 °C | 21.59 mm |
| Annual | 3.3 °C | 20.6 °C | 215.14 mm |
| 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 : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BWk - Cold Desert Climate |