Morgan City, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 15.5 °C (low) to 25.1 °C (high). Annual precipitation averages 1511.3 Millimeters. Morgan City is located in USDA Plant Hardiness Zone 9b.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 6.4 °C | 16.7 °C | 128.27 mm |
| February | 8.4 °C | 18.6 °C | 89.92 mm |
| March | 11.6 °C | 21.8 °C | 98.81 mm |
| April | 15.1 °C | 24.9 °C | 102.36 mm |
| May | 19.4 °C | 28.3 °C | 114.81 mm |
| June | 22.6 °C | 30.9 °C | 173.48 mm |
| July | 23.6 °C | 31.8 °C | 172.21 mm |
| August | 23.4 °C | 32.1 °C | 186.44 mm |
| September | 21.4 °C | 30.4 °C | 145.03 mm |
| October | 15.9 °C | 26.6 °C | 93.47 mm |
| November | 10.3 °C | 21.6 °C | 101.6 mm |
| December | 7.5 °C | 18 °C | 104.9 mm |
| Annual | 15.5 °C | 25.1 °C | 1511.3 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 |