Mamou, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 14.3 °C (low) to 25.9 °C (high). Annual precipitation averages 1544.6 Millimeters. Mamou is located in USDA Plant Hardiness Zone 9a. The growing season typically runs from the last frost around Feb. 21 - Feb. 29 through the first frost around Nov. 21 - Nov. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.9 °C | 16.1 °C | 167.13 mm |
| February | 6.9 °C | 18.4 °C | 124.71 mm |
| March | 10.3 °C | 22.2 °C | 105.66 mm |
| April | 14.1 °C | 26.2 °C | 127.76 mm |
| May | 18.7 °C | 29.7 °C | 133.1 mm |
| June | 22.1 °C | 32.7 °C | 139.7 mm |
| July | 23.1 °C | 33.5 °C | 121.41 mm |
| August | 22.7 °C | 33.8 °C | 123.19 mm |
| September | 20 °C | 31.6 °C | 126.75 mm |
| October | 14.2 °C | 27.4 °C | 118.87 mm |
| November | 9 °C | 21.4 °C | 126.49 mm |
| December | 6.1 °C | 17.4 °C | 129.79 mm |
| Annual | 14.3 °C | 25.9 °C | 1544.56 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| 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 |