Gueydan, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 15 °C (low) to 25.3 °C (high). Annual precipitation averages 1563.6 Millimeters. Gueydan is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Jan. 21 - Jan. 31 through the first frost around Dec. 21 - Dec. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 5.6 °C | 15.9 °C | 139.19 mm |
| February | 7.5 °C | 17.9 °C | 102.62 mm |
| March | 11 °C | 21.7 °C | 87.38 mm |
| April | 14.8 °C | 25.2 °C | 113.03 mm |
| May | 19.3 °C | 28.9 °C | 128.02 mm |
| June | 22.6 °C | 31.8 °C | 161.54 mm |
| July | 23.5 °C | 32.7 °C | 152.65 mm |
| August | 23.1 °C | 33 °C | 158.75 mm |
| September | 20.7 °C | 31.2 °C | 143.51 mm |
| October | 15.1 °C | 27.1 °C | 123.19 mm |
| November | 9.7 °C | 21.3 °C | 140.46 mm |
| December | 6.6 °C | 17.2 °C | 113.28 mm |
| Annual | 15 °C | 25.3 °C | 1563.62 mm |
| Average First Frost Date | Dec. 21 - Dec. 31 |
| Average Last Frost Date | Jan. 21 - Jan. 31 |
| 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 |