Forestville, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.2 °C (low) to 18.9 °C (high). Annual precipitation averages 1150.9 Millimeters. Forestville is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -3.2 °C | 6.3 °C | 76.96 mm |
| February | -2.4 °C | 8 °C | 67.31 mm |
| March | 1.4 °C | 12.5 °C | 99.82 mm |
| April | 7.1 °C | 18.8 °C | 87.38 mm |
| May | 12.4 °C | 23.5 °C | 109.98 mm |
| June | 17.6 °C | 28.2 °C | 116.33 mm |
| July | 20.2 °C | 30.8 °C | 118.11 mm |
| August | 19.2 °C | 29.8 °C | 92.46 mm |
| September | 15.5 °C | 26.2 °C | 112.52 mm |
| October | 8.8 °C | 19.8 °C | 97.03 mm |
| November | 3.1 °C | 13.8 °C | 78.23 mm |
| December | -0.8 °C | 8.5 °C | 94.74 mm |
| Annual | 8.2 °C | 18.9 °C | 1150.87 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |