Joppatowne, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.7 °C (low) to 18.5 °C (high). Annual precipitation averages 1253.7 Millimeters. Joppatowne 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 Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.9 °C | 5.7 °C | 87.38 mm |
| February | -2.2 °C | 7 °C | 70.61 mm |
| March | 1.6 °C | 11.5 °C | 111.76 mm |
| April | 7.4 °C | 18.3 °C | 93.73 mm |
| May | 12.8 °C | 23.4 °C | 107.95 mm |
| June | 18.1 °C | 28.3 °C | 119.63 mm |
| July | 20.9 °C | 30.7 °C | 116.33 mm |
| August | 19.9 °C | 29.8 °C | 111.25 mm |
| September | 16.1 °C | 26.3 °C | 124.71 mm |
| October | 9.6 °C | 19.9 °C | 117.09 mm |
| November | 3.7 °C | 13.4 °C | 85.85 mm |
| December | -0.3 °C | 8.1 °C | 107.44 mm |
| Annual | 8.7 °C | 18.5 °C | 1253.73 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| 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 |