Cabin John, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 8.8 °C (low) to 19.4 °C (high). Annual precipitation averages 1162.3 Millimeters. Cabin John is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.6 °C | 6.6 °C | 79.5 mm |
| February | -1.7 °C | 8.4 °C | 70.36 mm |
| March | 1.9 °C | 13.1 °C | 100.58 mm |
| April | 7.6 °C | 19.7 °C | 87.38 mm |
| May | 12.9 °C | 24.3 °C | 114.81 mm |
| June | 18 °C | 29 °C | 113.54 mm |
| July | 20.7 °C | 31.4 °C | 115.82 mm |
| August | 19.7 °C | 30.4 °C | 92.2 mm |
| September | 16.1 °C | 26.7 °C | 114.05 mm |
| October | 9.3 °C | 20.3 °C | 99.57 mm |
| November | 3.6 °C | 14.2 °C | 81.53 mm |
| December | -0.2 °C | 8.8 °C | 92.96 mm |
| Annual | 8.8 °C | 19.4 °C | 1162.3 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 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 | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |