Green Valley, Maryland has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 44.7 °F (low) to 64.9 °F (high). Annual precipitation averages 45.4 Inches. Green Valley 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 | 24.4 °F | 41.3 °F | 3.12 in. |
| February | 25.9 °F | 44.5 °F | 2.71 in. |
| March | 32.6 °F | 53.3 °F | 3.88 in. |
| April | 42.3 °F | 65.5 °F | 3.46 in. |
| May | 52.4 °F | 74.2 °F | 4.35 in. |
| June | 61.3 °F | 82.6 °F | 4.52 in. |
| July | 66.3 °F | 86.9 °F | 4.36 in. |
| August | 64.1 °F | 85.0 °F | 3.48 in. |
| September | 57.3 °F | 78.4 °F | 4.52 in. |
| October | 45.7 °F | 66.8 °F | 3.93 in. |
| November | 35.4 °F | 55.5 °F | 3.34 in. |
| December | 28.9 °F | 45.3 °F | 3.68 in. |
| Annual | 44.7 °F | 64.9 °F | 45.35 in. |
| 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 : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |