Glen Rose, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.8 °C (low) to 25.8 °C (high). Annual precipitation averages 919.2 Millimeters. Glen Rose is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.4 °C | 14.8 °C | 55.12 mm |
| February | 2.7 °C | 17.2 °C | 62.74 mm |
| March | 7 °C | 21.3 °C | 84.58 mm |
| April | 11.4 °C | 25.8 °C | 78.99 mm |
| May | 16.7 °C | 29.7 °C | 117.35 mm |
| June | 21 °C | 33.7 °C | 103.63 mm |
| July | 22.7 °C | 36.2 °C | 45.72 mm |
| August | 22.3 °C | 36.4 °C | 64.77 mm |
| September | 18.2 °C | 32.5 °C | 81.28 mm |
| October | 12 °C | 26.7 °C | 101.09 mm |
| November | 6.2 °C | 20.1 °C | 64.01 mm |
| December | 1.4 °C | 15.6 °C | 59.94 mm |
| Annual | 11.8 °C | 25.8 °C | 919.22 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |