Onalaska, 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 1334.5 Millimeters. Onalaska 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 | 3.7 °C | 16.2 °C | 115.32 mm |
| February | 5.7 °C | 18.4 °C | 94.49 mm |
| March | 9.2 °C | 22.2 °C | 102.36 mm |
| April | 12.8 °C | 25.9 °C | 99.06 mm |
| May | 17.7 °C | 29.6 °C | 125.98 mm |
| June | 21.2 °C | 32.9 °C | 129.29 mm |
| July | 22.4 °C | 34.4 °C | 89.15 mm |
| August | 22.2 °C | 35 °C | 111.51 mm |
| September | 19.1 °C | 31.9 °C | 101.6 mm |
| October | 13.6 °C | 27.3 °C | 125.22 mm |
| November | 8.2 °C | 21.3 °C | 119.38 mm |
| December | 4.6 °C | 16.9 °C | 121.16 mm |
| Annual | 13.4 °C | 26 °C | 1334.52 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 |