Jarrell, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 13.2 °C (low) to 25.9 °C (high). Annual precipitation averages 909.1 Millimeters. Jarrell is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.7 °C | 15.7 °C | 63.5 mm |
| February | 4.7 °C | 17.7 °C | 57.15 mm |
| March | 8.7 °C | 21.5 °C | 77.98 mm |
| April | 12.7 °C | 25.6 °C | 70.36 mm |
| May | 17.7 °C | 29.4 °C | 111.25 mm |
| June | 21.5 °C | 33.3 °C | 87.88 mm |
| July | 22.7 °C | 35.2 °C | 52.83 mm |
| August | 22.6 °C | 35.7 °C | 68.07 mm |
| September | 19.3 °C | 32.2 °C | 85.6 mm |
| October | 13.7 °C | 27 °C | 93.47 mm |
| November | 7.9 °C | 20.8 °C | 74.17 mm |
| December | 3.6 °C | 16.4 °C | 66.8 mm |
| Annual | 13.2 °C | 25.9 °C | 909.06 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |