Belle Chasse, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 16.1 °C (low) to 25.8 °C (high). Annual precipitation averages 1681.2 Millimeters. Belle Chasse is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.8 °C | 16.8 °C | 138.94 mm |
| February | 8.7 °C | 18.9 °C | 106.43 mm |
| March | 11.9 °C | 22.2 °C | 117.09 mm |
| April | 15.6 °C | 25.8 °C | 132.08 mm |
| May | 19.8 °C | 29.6 °C | 135.38 mm |
| June | 23 °C | 32.2 °C | 175.26 mm |
| July | 24 °C | 33.1 °C | 188.21 mm |
| August | 24.1 °C | 33 °C | 205.99 mm |
| September | 22.2 °C | 31.1 °C | 151.38 mm |
| October | 17.1 °C | 27 °C | 102.87 mm |
| November | 11.3 °C | 21.7 °C | 100.84 mm |
| December | 8.2 °C | 18.2 °C | 126.75 mm |
| Annual | 16.1 °C | 25.8 °C | 1681.22 mm |
| Average First Frost Date | Frost Rare |
| Average Last Frost Date | |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9b : -3.9°C to -1.1°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 |