Santo, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 11.9 °C (low) to 25.4 °C (high). Annual precipitation averages 836.2 Millimeters. Santo is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 0.4 °C | 14.6 °C | 43.94 mm |
| February | 2.3 °C | 16.4 °C | 56.9 mm |
| March | 6.8 °C | 20.7 °C | 72.39 mm |
| April | 11.2 °C | 25.4 °C | 69.85 mm |
| May | 16.6 °C | 29.2 °C | 107.7 mm |
| June | 21.3 °C | 33.4 °C | 91.69 mm |
| July | 23.2 °C | 35.8 °C | 51.56 mm |
| August | 22.7 °C | 35.9 °C | 63.25 mm |
| September | 18.4 °C | 31.9 °C | 80.01 mm |
| October | 12.2 °C | 26.3 °C | 92.2 mm |
| November | 6.2 °C | 19.8 °C | 58.67 mm |
| December | 1.3 °C | 15.1 °C | 48.01 mm |
| Annual | 11.9 °C | 25.4 °C | 836.17 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 8a : -12.2°C to -9.4°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |