Sunnyvale, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 12.7 °C (low) to 24.5 °C (high). Annual precipitation averages 1090.7 Millimeters. Sunnyvale 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 | 1.7 °C | 13.3 °C | 72.39 mm |
| February | 3.7 °C | 15.6 °C | 78.23 mm |
| March | 7.7 °C | 19.7 °C | 97.03 mm |
| April | 11.9 °C | 23.9 °C | 105.41 mm |
| May | 17.2 °C | 27.9 °C | 127.25 mm |
| June | 21.6 °C | 32.5 °C | 102.62 mm |
| July | 23.2 °C | 34.8 °C | 55.37 mm |
| August | 22.9 °C | 35.1 °C | 61.98 mm |
| September | 19.2 °C | 31.4 °C | 81.79 mm |
| October | 12.9 °C | 25.8 °C | 130.56 mm |
| November | 7.2 °C | 19.4 °C | 85.6 mm |
| December | 2.7 °C | 14.4 °C | 92.46 mm |
| Annual | 12.7 °C | 24.5 °C | 1090.69 mm |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 8b : -9.4°C to -6.7°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 |