Groom, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 6.7 °C (low) to 22 °C (high). Annual precipitation averages 565.4 Millimeters. Groom 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 | -4.6 °C | 10.3 °C | 17.78 mm |
| February | -3.3 °C | 12.4 °C | 15.49 mm |
| March | 0.9 °C | 17.3 °C | 35.56 mm |
| April | 5.4 °C | 21.9 °C | 46.74 mm |
| May | 11.1 °C | 26.5 °C | 73.66 mm |
| June | 16.6 °C | 31.4 °C | 82.3 mm |
| July | 18.7 °C | 33.6 °C | 66.04 mm |
| August | 18 °C | 32.8 °C | 77.98 mm |
| September | 13.8 °C | 28.6 °C | 53.34 mm |
| October | 7 °C | 22.6 °C | 53.09 mm |
| November | 0.3 °C | 15.9 °C | 21.59 mm |
| December | -4.1 °C | 10.4 °C | 21.84 mm |
| Annual | 6.7 °C | 22 °C | 565.41 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 | Extreme Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |