Lake Sumner, New Mexico has a Cold Semi-Arid Climate climate (Köppen classification: BSk). Average annual temperatures range from 6.4 °C (low) to 23.5 °C (high). Annual precipitation averages 338.1 Millimeters. Lake Sumner 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.3 °C | 12.3 °C | 7.62 mm |
| February | -2.7 °C | 14.9 °C | 6.6 mm |
| March | 1.2 °C | 19.2 °C | 16.26 mm |
| April | 5.1 °C | 23.7 °C | 19.3 mm |
| May | 10.6 °C | 28.5 °C | 25.15 mm |
| June | 15.8 °C | 33.6 °C | 37.34 mm |
| July | 18.3 °C | 34.3 °C | 64.26 mm |
| August | 17.5 °C | 33.2 °C | 54.86 mm |
| September | 13.3 °C | 29.6 °C | 47.5 mm |
| October | 6.3 °C | 23.7 °C | 33.53 mm |
| November | 0 °C | 17.2 °C | 13.46 mm |
| December | -4 °C | 12.3 °C | 12.19 mm |
| Annual | 6.4 °C | 23.5 °C | 338.07 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| 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 |