Erath, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 14.7 °C (low) to 25.5 °C (high). Annual precipitation averages 1618.8 Millimeters. Erath 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 | 16.5 °C | 147.07 mm |
| February | 7.5 °C | 18.4 °C | 107.44 mm |
| March | 10.9 °C | 22.1 °C | 96.01 mm |
| April | 14.5 °C | 25.4 °C | 131.57 mm |
| May | 18.9 °C | 29.1 °C | 123.95 mm |
| June | 22.3 °C | 31.8 °C | 176.02 mm |
| July | 23.4 °C | 32.6 °C | 171.2 mm |
| August | 22.8 °C | 32.8 °C | 173.48 mm |
| September | 20.5 °C | 31.2 °C | 140.21 mm |
| October | 14.8 °C | 27.2 °C | 121.67 mm |
| November | 9.3 °C | 21.7 °C | 117.35 mm |
| December | 6.4 °C | 17.7 °C | 112.78 mm |
| Annual | 14.7 °C | 25.5 °C | 1618.75 mm |
| Average First Frost Date | Dec. 21 - Dec. 31 |
| 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 9a : -6.7°C to -3.9°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |