Union Bridge, Maryland has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.7 °F (low) to 64.7 °F (high). Annual precipitation averages 45 Inches. Union Bridge is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 23.1 °F | 40.3 °F | 3.28 in. |
| February | 24.8 °F | 43.8 °F | 2.62 in. |
| March | 31.4 °F | 52.6 °F | 3.82 in. |
| April | 41.4 °F | 65.2 °F | 3.5 in. |
| May | 51.3 °F | 74.2 °F | 4.1 in. |
| June | 60.5 °F | 82.7 °F | 4.08 in. |
| July | 65.3 °F | 87.3 °F | 4.36 in. |
| August | 63.3 °F | 85.1 °F | 3.47 in. |
| September | 56.3 °F | 78.5 °F | 4.81 in. |
| October | 44.8 °F | 66.7 °F | 3.92 in. |
| November | 34.4 °F | 55.2 °F | 3.29 in. |
| December | 28.0 °F | 44.7 °F | 3.72 in. |
| Annual | 43.7 °F | 64.7 °F | 44.97 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| 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 | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |