Dundalk, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.5 °C (low) to 18.5 °C (high). Annual precipitation averages 1199.9 Millimeters. Dundalk is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.2 °C | 5.9 °C | 84.58 mm |
| February | -1.5 °C | 7.2 °C | 72.9 mm |
| March | 2.3 °C | 11.5 °C | 108.2 mm |
| April | 8.1 °C | 18 °C | 92.46 mm |
| May | 13.5 °C | 23.1 °C | 105.92 mm |
| June | 18.8 °C | 28.2 °C | 113.28 mm |
| July | 21.7 °C | 30.7 °C | 110.74 mm |
| August | 20.9 °C | 29.7 °C | 102.62 mm |
| September | 17.2 °C | 26 °C | 118.11 mm |
| October | 10.6 °C | 19.7 °C | 107.19 mm |
| November | 4.6 °C | 13.5 °C | 83.31 mm |
| December | 0.3 °C | 8.2 °C | 100.58 mm |
| Annual | 9.5 °C | 18.5 °C | 1199.89 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 8a : -12.2°C to -9.4°C |
| Plant Hardiness Zone - 2012 | Zone 7b : -15°C to -12.2°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |