Riverside, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 13.4 °C (low) to 26 °C (high). Annual precipitation averages 1240.8 Millimeters. Riverside is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 11 - Feb. 20 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.7 °C | 16.2 °C | 106.17 mm |
| February | 5.7 °C | 18.3 °C | 89.92 mm |
| March | 9.2 °C | 22.2 °C | 105.66 mm |
| April | 12.8 °C | 25.8 °C | 96.77 mm |
| May | 17.7 °C | 29.6 °C | 115.06 mm |
| June | 21.2 °C | 32.9 °C | 116.08 mm |
| July | 22.4 °C | 34.3 °C | 84.58 mm |
| August | 22.2 °C | 35.1 °C | 101.35 mm |
| September | 19.2 °C | 32.1 °C | 97.28 mm |
| October | 13.6 °C | 27.4 °C | 104.39 mm |
| November | 8.1 °C | 21.4 °C | 114.05 mm |
| December | 4.6 °C | 17 °C | 109.47 mm |
| Annual | 13.4 °C | 26 °C | 1240.78 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 11 - Feb. 20 |
| Average Days With Frost | 10-20 Days |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°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 |