Adamstown, Maryland has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7.1 °C (low) to 18.7 °C (high). Annual precipitation averages 1091.2 Millimeters. Adamstown is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.2 °C | 5.3 °C | 75.95 mm |
| February | -3.4 °C | 7 °C | 62.23 mm |
| March | 0.2 °C | 12 °C | 91.19 mm |
| April | 5.8 °C | 18.9 °C | 84.84 mm |
| May | 11.4 °C | 23.9 °C | 107.44 mm |
| June | 16.4 °C | 28.6 °C | 103.63 mm |
| July | 19.3 °C | 31.2 °C | 107.44 mm |
| August | 18.1 °C | 30.1 °C | 81.79 mm |
| September | 14.1 °C | 26.3 °C | 114.05 mm |
| October | 7.7 °C | 19.9 °C | 92.71 mm |
| November | 1.7 °C | 13.4 °C | 79.25 mm |
| December | -1.7 °C | 7.7 °C | 90.68 mm |
| Annual | 7.1 °C | 18.7 °C | 1091.2 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |