Alexandria, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.4 °C (low) to 16.6 °C (high). Annual precipitation averages 1038.6 Millimeters. Alexandria 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 | -6.8 °C | 2.8 °C | 71.12 mm |
| February | -6.3 °C | 4.6 °C | 58.42 mm |
| March | -2.7 °C | 9.4 °C | 82.04 mm |
| April | 2.8 °C | 16.8 °C | 89.92 mm |
| May | 8.7 °C | 22.5 °C | 101.6 mm |
| June | 13.9 °C | 26.9 °C | 100.33 mm |
| July | 16.2 °C | 29.3 °C | 95.25 mm |
| August | 15.3 °C | 28.4 °C | 95.25 mm |
| September | 11.3 °C | 24.6 °C | 101.35 mm |
| October | 4.9 °C | 17.9 °C | 89.66 mm |
| November | -0.2 °C | 11.3 °C | 75.44 mm |
| December | -4.1 °C | 5.1 °C | 78.23 mm |
| Annual | 4.4 °C | 16.6 °C | 1038.61 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| 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 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |