Portales, New Mexico has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 6 °C (low) to 23.4 °C (high). Annual precipitation averages 402.8 Millimeters. Portales is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.8 °C | 12.1 °C | 11.94 mm |
| February | -3.2 °C | 14.8 °C | 9.65 mm |
| March | 0.4 °C | 19.2 °C | 20.57 mm |
| April | 4.4 °C | 23.9 °C | 17.27 mm |
| May | 10.3 °C | 28.4 °C | 40.39 mm |
| June | 15.8 °C | 33.2 °C | 46.99 mm |
| July | 17.8 °C | 33.7 °C | 59.94 mm |
| August | 17.1 °C | 32.8 °C | 69.34 mm |
| September | 12.9 °C | 29.2 °C | 50.8 mm |
| October | 6.2 °C | 23.9 °C | 43.69 mm |
| November | -0.3 °C | 17.2 °C | 15.24 mm |
| December | -4.3 °C | 12.3 °C | 17.02 mm |
| Annual | 6 °C | 23.4 °C | 402.84 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | BSk - Cold Semi-Arid Climate |