Bartonsville, Maryland has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7 °C (low) to 18.3 °C (high). Annual precipitation averages 1120.1 Millimeters. Bartonsville is located in USDA Plant Hardiness Zone 7a. 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 | -4.3 °C | 4.9 °C | 76.71 mm |
| February | -3.4 °C | 6.8 °C | 62.74 mm |
| March | 0.2 °C | 11.7 °C | 93.47 mm |
| April | 5.7 °C | 18.5 °C | 85.85 mm |
| May | 11.2 °C | 23.4 °C | 105.41 mm |
| June | 16.2 °C | 28.2 °C | 102.87 mm |
| July | 18.9 °C | 30.7 °C | 123.7 mm |
| August | 17.8 °C | 29.6 °C | 82.55 mm |
| September | 13.9 °C | 25.8 °C | 115.82 mm |
| October | 7.6 °C | 19.4 °C | 97.03 mm |
| November | 1.8 °C | 13 °C | 81.28 mm |
| December | -1.8 °C | 7.3 °C | 92.71 mm |
| Annual | 7 °C | 18.3 °C | 1120.14 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 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |