Bel Air, Maryland has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.8 °C (low) to 18.4 °C (high). Annual precipitation averages 1057.6 Millimeters. Bel Air 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 | -4.8 °C | 4.7 °C | 72.9 mm |
| February | -4.1 °C | 6.8 °C | 65.02 mm |
| March | -0.6 °C | 11.8 °C | 87.88 mm |
| April | 4.6 °C | 19.3 °C | 93.22 mm |
| May | 9.8 °C | 24.1 °C | 117.09 mm |
| June | 14.8 °C | 28.3 °C | 107.7 mm |
| July | 17.2 °C | 30.7 °C | 91.44 mm |
| August | 16.3 °C | 29.8 °C | 90.42 mm |
| September | 12.4 °C | 26.2 °C | 102.62 mm |
| October | 6 °C | 19.7 °C | 78.99 mm |
| November | 0.7 °C | 12.7 °C | 67.56 mm |
| December | -2.6 °C | 6.8 °C | 82.8 mm |
| Annual | 5.8 °C | 18.4 °C | 1057.64 mm |
| 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 : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |