Shelbyville, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12.3 °C (low) to 25.2 °C (high). Annual precipitation averages 1396.3 Millimeters. Shelbyville is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 2.4 °C | 14.9 °C | 128.78 mm |
| February | 4.3 °C | 17.2 °C | 117.86 mm |
| March | 7.8 °C | 21.2 °C | 131.57 mm |
| April | 11.7 °C | 25 °C | 122.94 mm |
| May | 16.8 °C | 28.8 °C | 112.78 mm |
| June | 20.8 °C | 32.3 °C | 121.16 mm |
| July | 22.2 °C | 34.2 °C | 86.87 mm |
| August | 21.7 °C | 34.6 °C | 97.03 mm |
| September | 18.3 °C | 31.7 °C | 91.69 mm |
| October | 11.9 °C | 26.4 °C | 123.95 mm |
| November | 6.7 °C | 20.1 °C | 118.87 mm |
| December | 3.2 °C | 15.6 °C | 142.75 mm |
| Annual | 12.3 °C | 25.2 °C | 1396.25 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 30-40 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 | Abnormally Dry |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |