Opelousas, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 14.2 °C (low) to 25.6 °C (high). Annual precipitation averages 1643.1 Millimeters. Opelousas 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 | 4.9 °C | 16.3 °C | 176.78 mm |
| February | 6.9 °C | 18.3 °C | 127 mm |
| March | 10.3 °C | 22.2 °C | 111 mm |
| April | 13.8 °C | 25.6 °C | 127.76 mm |
| May | 18.5 °C | 29.3 °C | 139.19 mm |
| June | 21.9 °C | 32.1 °C | 161.8 mm |
| July | 22.9 °C | 32.8 °C | 140.21 mm |
| August | 22.5 °C | 33.3 °C | 144.78 mm |
| September | 19.9 °C | 31.3 °C | 133.35 mm |
| October | 14.1 °C | 26.9 °C | 127 mm |
| November | 8.8 °C | 21.4 °C | 124.21 mm |
| December | 6 °C | 17.4 °C | 130.05 mm |
| Annual | 14.2 °C | 25.6 °C | 1643.13 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 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |