Richwood, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 16.2 °C (low) to 26.2 °C (high). Annual precipitation averages 1227.8 Millimeters. Richwood is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.8 °C | 17.7 °C | 102.87 mm |
| February | 9 °C | 19.3 °C | 67.56 mm |
| March | 12.2 °C | 22.4 °C | 77.22 mm |
| April | 15.8 °C | 25.7 °C | 81.28 mm |
| May | 20.1 °C | 29.2 °C | 98.81 mm |
| June | 23.2 °C | 32.1 °C | 113.03 mm |
| July | 24.1 °C | 33.1 °C | 101.85 mm |
| August | 23.9 °C | 33.6 °C | 120.9 mm |
| September | 21.8 °C | 31.6 °C | 154.94 mm |
| October | 17.6 °C | 28 °C | 108.71 mm |
| November | 12.2 °C | 22.9 °C | 102.87 mm |
| December | 7.9 °C | 18.9 °C | 97.79 mm |
| Annual | 16.2 °C | 26.2 °C | 1227.83 mm |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9b : -3.9°C to -1.1°C |
| Plant Hardiness Zone - 2012 | Zone 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |