Castor, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 54.1 °F (low) to 76.7 °F (high). Annual precipitation averages 56.7 Inches. Castor is located in USDA Plant Hardiness Zone 8b. The growing season typically runs from the last frost around Mar. 11 - Mar. 20 through the first frost around Nov. 11 - Nov. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 35.8 °F | 57.5 °F | 5.46 in. |
| February | 38.8 °F | 61.9 °F | 5.08 in. |
| March | 45.6 °F | 69.3 °F | 5.31 in. |
| April | 52.9 °F | 76.6 °F | 5.26 in. |
| May | 62.1 °F | 83.5 °F | 4.66 in. |
| June | 69.5 °F | 90.0 °F | 4.48 in. |
| July | 72.3 °F | 93.1 °F | 3.96 in. |
| August | 71.5 °F | 93.7 °F | 3.65 in. |
| September | 65.0 °F | 88.6 °F | 3.8 in. |
| October | 53.6 °F | 78.8 °F | 4.49 in. |
| November | 43.8 °F | 67.9 °F | 4.85 in. |
| December | 37.7 °F | 59.6 °F | 5.69 in. |
| Annual | 54.1 °F | 76.7 °F | 56.69 in. |
| Average First Frost Date | Nov. 11 - Nov. 20 |
| Average Last Frost Date | Mar. 11 - Mar. 20 |
| Average Days With Frost | 40-50 Days |
| Plant Hardiness Zone | Zone 8b : 15°F to 20°F |
| Plant Hardiness Zone - 2012 | Zone 8a : 10°F to 15°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |