Trinity, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 13.2 °C (low) to 25.9 °C (high). Annual precipitation averages 1239.8 Millimeters. Trinity is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 3.3 °C | 15.9 °C | 107.7 mm |
| February | 5.3 °C | 18.1 °C | 90.42 mm |
| March | 8.8 °C | 21.9 °C | 103.12 mm |
| April | 12.6 °C | 25.6 °C | 95.25 mm |
| May | 17.6 °C | 29.3 °C | 116.33 mm |
| June | 21.2 °C | 32.8 °C | 117.6 mm |
| July | 22.5 °C | 34.4 °C | 83.57 mm |
| August | 22.2 °C | 35.2 °C | 98.3 mm |
| September | 19.1 °C | 32.1 °C | 96.27 mm |
| October | 13.3 °C | 27.3 °C | 107.95 mm |
| November | 7.9 °C | 21.2 °C | 111.76 mm |
| December | 4.2 °C | 16.7 °C | 111.51 mm |
| Annual | 13.2 °C | 25.9 °C | 1239.78 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 20-30 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 |