Hammond, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 13.8 °C (low) to 25.9 °C (high). Annual precipitation averages 1653 Millimeters. Hammond 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 Jan. 1 - Jan. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.6 °C | 16.6 °C | 148.84 mm |
| February | 6.3 °C | 18.8 °C | 128.02 mm |
| March | 9.7 °C | 22.5 °C | 135.13 mm |
| April | 12.9 °C | 26 °C | 134.87 mm |
| May | 17.4 °C | 29.7 °C | 137.41 mm |
| June | 21.1 °C | 32.6 °C | 171.45 mm |
| July | 22.3 °C | 33.4 °C | 168.66 mm |
| August | 22.2 °C | 33.6 °C | 167.89 mm |
| September | 19.9 °C | 31.5 °C | 120.9 mm |
| October | 14.3 °C | 27.2 °C | 102.87 mm |
| November | 8.7 °C | 21.4 °C | 100.33 mm |
| December | 5.6 °C | 17.8 °C | 136.65 mm |
| Annual | 13.8 °C | 25.9 °C | 1653.02 mm |
| Average First Frost Date | Jan. 1 - Jan. 10 |
| Average Last Frost Date | Jan. 21 - Jan. 31 |
| Average Days With Frost | Frost Rare |
| Plant Hardiness Zone | Zone 9a : -6.7°C to -3.9°C |
| Plant Hardiness Zone - 2012 | Zone 8b : -9.4°C to -6.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |