Middletown, Maryland has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 6.7 °C (low) to 18.2 °C (high). Annual precipitation averages 1094 Millimeters. Middletown 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -4.3 °C | 4.9 °C | 77.72 mm |
| February | -3.7 °C | 6.9 °C | 62.48 mm |
| March | 0.3 °C | 11.6 °C | 92.71 mm |
| April | 5.6 °C | 18.4 °C | 90.68 mm |
| May | 10.9 °C | 23.3 °C | 109.22 mm |
| June | 15.9 °C | 28 °C | 100.84 mm |
| July | 18.3 °C | 30.6 °C | 104.14 mm |
| August | 17.3 °C | 29.4 °C | 83.06 mm |
| September | 13.5 °C | 25.7 °C | 111.76 mm |
| October | 7.4 °C | 19.3 °C | 91.95 mm |
| November | 1.8 °C | 12.9 °C | 80.01 mm |
| December | -2.1 °C | 7.1 °C | 89.41 mm |
| Annual | 6.7 °C | 18.2 °C | 1093.98 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 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 |