Poolesville, Maryland has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7.3 °C (low) to 18.4 °C (high). Annual precipitation averages 1160.3 Millimeters. Poolesville is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4 °C | 5.4 °C | 76.2 mm |
| February | -3.1 °C | 7.2 °C | 67.31 mm |
| March | 0.6 °C | 11.9 °C | 97.03 mm |
| April | 6.2 °C | 18.7 °C | 85.6 mm |
| May | 11.7 °C | 23.3 °C | 113.54 mm |
| June | 16.6 °C | 28.1 °C | 113.03 mm |
| July | 19.3 °C | 30.6 °C | 105.92 mm |
| August | 18.2 °C | 29.7 °C | 86.61 mm |
| September | 14.4 °C | 25.9 °C | 119.89 mm |
| October | 7.7 °C | 19.5 °C | 106.68 mm |
| November | 2.1 °C | 13.2 °C | 88.39 mm |
| December | -1.7 °C | 7.6 °C | 100.08 mm |
| Annual | 7.3 °C | 18.4 °C | 1160.28 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 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 | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |