New Ulm, Texas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 58 °F (low) to 78.9 °F (high). Annual precipitation averages 43.1 Inches. New Ulm is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Mar. 1 - Mar. 10 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 40.8 °F | 61.3 °F | 3.44 in. |
| February | 44.5 °F | 64.9 °F | 2.81 in. |
| March | 50.9 °F | 71.4 °F | 3.33 in. |
| April | 57.3 °F | 78.4 °F | 3.38 in. |
| May | 65.1 °F | 84.9 °F | 4.72 in. |
| June | 71.9 °F | 91.1 °F | 4.22 in. |
| July | 73.4 °F | 93.3 °F | 2.4 in. |
| August | 73.4 °F | 96.2 °F | 3.38 in. |
| September | 68.4 °F | 90.4 °F | 3.62 in. |
| October | 58.8 °F | 81.0 °F | 4.5 in. |
| November | 48.7 °F | 70.8 °F | 3.8 in. |
| December | 42.3 °F | 63.3 °F | 3.51 in. |
| Annual | 58 °F | 78.9 °F | 43.11 in. |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Mar. 1 - Mar. 10 |
| Average Days With Frost | 20-30 Days |
| Plant Hardiness Zone | Zone 9a : 20°F to 25°F |
| Plant Hardiness Zone - 2012 | Zone 8b : 15°F to 20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |