Jennings, Maryland has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 3.3 °C (low) to 14.6 °C (high). Annual precipitation averages 1219.5 Millimeters. Jennings is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.9 °C | 1.3 °C | 94.74 mm |
| February | -7.1 °C | 3.1 °C | 88.9 mm |
| March | -3.6 °C | 7.7 °C | 104.9 mm |
| April | 1.9 °C | 15.5 °C | 109.22 mm |
| May | 7.7 °C | 20.3 °C | 128.78 mm |
| June | 12.4 °C | 24.2 °C | 127.51 mm |
| July | 14.6 °C | 26.3 °C | 110.24 mm |
| August | 13.7 °C | 25.6 °C | 96.27 mm |
| September | 9.9 °C | 22.2 °C | 96.01 mm |
| October | 4 °C | 15.9 °C | 83.57 mm |
| November | -1.3 °C | 9.2 °C | 81.79 mm |
| December | -5.1 °C | 3.6 °C | 97.54 mm |
| Annual | 3.3 °C | 14.6 °C | 1219.47 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |