Middleburg, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.8 °C (low) to 16.3 °C (high). Annual precipitation averages 1164.8 Millimeters. Middleburg is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.9 °C | 2.2 °C | 82.04 mm |
| February | -6.3 °C | 3.9 °C | 62.23 mm |
| March | -2.2 °C | 9.1 °C | 89.15 mm |
| April | 3.4 °C | 16.6 °C | 96.52 mm |
| May | 9.2 °C | 22.3 °C | 105.16 mm |
| June | 14.4 °C | 26.8 °C | 109.22 mm |
| July | 16.7 °C | 29.3 °C | 108.71 mm |
| August | 15.8 °C | 28.2 °C | 111.76 mm |
| September | 11.7 °C | 24.4 °C | 121.16 mm |
| October | 5.5 °C | 17.7 °C | 106.68 mm |
| November | 0.1 °C | 10.9 °C | 81.53 mm |
| December | -3.8 °C | 4.7 °C | 90.68 mm |
| Annual | 4.8 °C | 16.3 °C | 1164.84 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |