Reisterstown, Maryland has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 7 °C (low) to 18.2 °C (high). Annual precipitation averages 1199.4 Millimeters. Reisterstown 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 | -4.4 °C | 4.9 °C | 88.39 mm |
| February | -3.4 °C | 6.6 °C | 71.63 mm |
| March | 0.2 °C | 11.5 °C | 105.92 mm |
| April | 5.9 °C | 18.6 °C | 95 mm |
| May | 11.1 °C | 23.7 °C | 111 mm |
| June | 16.2 °C | 28.3 °C | 104.9 mm |
| July | 18.7 °C | 30.6 °C | 114.3 mm |
| August | 17.7 °C | 29.4 °C | 90.93 mm |
| September | 14.1 °C | 25.8 °C | 124.46 mm |
| October | 7.7 °C | 19.2 °C | 108.46 mm |
| November | 2.4 °C | 12.8 °C | 84.33 mm |
| December | -1.7 °C | 7.2 °C | 100.08 mm |
| Annual | 7 °C | 18.2 °C | 1199.4 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 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 | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |