Forest Hill, Louisiana has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 13.1 °C (low) to 25.3 °C (high). Annual precipitation averages 1544.8 Millimeters. Forest Hill 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 | 3.3 °C | 15.1 °C | 157.99 mm |
| February | 5.2 °C | 17.6 °C | 128.78 mm |
| March | 8.9 °C | 21.7 °C | 117.86 mm |
| April | 12.7 °C | 25.4 °C | 133.35 mm |
| May | 17.5 °C | 29.3 °C | 122.94 mm |
| June | 21.1 °C | 32.3 °C | 129.79 mm |
| July | 22.4 °C | 33.6 °C | 120.9 mm |
| August | 22.1 °C | 34 °C | 110.74 mm |
| September | 19.2 °C | 31.4 °C | 113.03 mm |
| October | 12.9 °C | 26.6 °C | 121.16 mm |
| November | 7.4 °C | 20.6 °C | 141.22 mm |
| December | 4.4 °C | 16.3 °C | 147.07 mm |
| Annual | 13.1 °C | 25.3 °C | 1544.83 mm |
| Average First Frost Date | Nov. 21 - Nov. 30 |
| Average Last Frost Date | Feb. 21 - Feb. 29 |
| Average Days With Frost | 20-30 Days |
| 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 |