Callaway, Maryland has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 9.4 °C (low) to 19.2 °C (high). Annual precipitation averages 1162.8 Millimeters. Callaway is located in USDA Plant Hardiness Zone 8a. The growing season typically runs from the last frost around Mar. 21 - Mar. 31 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -1.9 °C | 7.3 °C | 81.28 mm |
| February | -1.1 °C | 8.7 °C | 72.39 mm |
| March | 2.5 °C | 12.8 °C | 105.66 mm |
| April | 8.1 °C | 18.9 °C | 85.34 mm |
| May | 13.4 °C | 23.4 °C | 98.81 mm |
| June | 18.4 °C | 28.2 °C | 106.68 mm |
| July | 21.1 °C | 30.4 °C | 115.82 mm |
| August | 20.2 °C | 29.4 °C | 109.22 mm |
| September | 16.8 °C | 26.3 °C | 108.2 mm |
| October | 10.3 °C | 20.3 °C | 103.89 mm |
| November | 4.5 °C | 14.6 °C | 81.79 mm |
| December | 0.8 °C | 9.7 °C | 93.73 mm |
| Annual | 9.4 °C | 19.2 °C | 1162.81 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Mar. 21 - Mar. 31 |
| Average Days With Frost | 50-75 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 |