Cecilia, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 14.6 °C (low) to 25.7 °C (high). Annual precipitation averages 1616.5 Millimeters. Cecilia 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 | 5.6 °C | 16.7 °C | 164.85 mm |
| February | 7.4 °C | 18.7 °C | 118.11 mm |
| March | 10.9 °C | 22.4 °C | 104.14 mm |
| April | 14.2 °C | 25.7 °C | 131.83 mm |
| May | 18.7 °C | 29.4 °C | 142.75 mm |
| June | 22.1 °C | 32.1 °C | 165.35 mm |
| July | 23.2 °C | 32.8 °C | 143.51 mm |
| August | 22.7 °C | 33.1 °C | 149.1 mm |
| September | 20.3 °C | 31.2 °C | 131.57 mm |
| October | 14.5 °C | 27.1 °C | 119.38 mm |
| November | 9.2 °C | 21.8 °C | 120.65 mm |
| December | 6.5 °C | 17.9 °C | 125.22 mm |
| Annual | 14.6 °C | 25.7 °C | 1616.46 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 |