Frederick, Maryland has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7.1 °C (low) to 18.5 °C (high). Annual precipitation averages 1084.6 Millimeters. Frederick is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.2 °C | 5.1 °C | 74.17 mm |
| February | -3.4 °C | 6.9 °C | 60.45 mm |
| March | 0.2 °C | 11.8 °C | 90.68 mm |
| April | 5.8 °C | 18.8 °C | 85.09 mm |
| May | 11.3 °C | 23.7 °C | 105.16 mm |
| June | 16.4 °C | 28.4 °C | 99.06 mm |
| July | 19.2 °C | 31.1 °C | 116.33 mm |
| August | 18 °C | 29.9 °C | 77.47 mm |
| September | 14 °C | 26.1 °C | 114.81 mm |
| October | 7.7 °C | 19.7 °C | 92.71 mm |
| November | 1.8 °C | 13.2 °C | 76.71 mm |
| December | -1.7 °C | 7.6 °C | 91.95 mm |
| Annual | 7.1 °C | 18.5 °C | 1084.59 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 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 | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |