Birmingham, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.5 °C (low) to 15.5 °C (high). Annual precipitation averages 1099.6 Millimeters. Birmingham is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.1 °C | 1.7 °C | 74.93 mm |
| February | -6.6 °C | 3.3 °C | 65.79 mm |
| March | -2.7 °C | 8.2 °C | 87.12 mm |
| April | 3.3 °C | 15.7 °C | 95.5 mm |
| May | 8.9 °C | 21.4 °C | 104.65 mm |
| June | 13.9 °C | 25.7 °C | 106.68 mm |
| July | 16.2 °C | 28.1 °C | 100.33 mm |
| August | 15.4 °C | 27.2 °C | 97.03 mm |
| September | 11.4 °C | 23.4 °C | 108.2 mm |
| October | 5.3 °C | 16.8 °C | 95.5 mm |
| November | 0.1 °C | 10.1 °C | 80.52 mm |
| December | -4 °C | 3.9 °C | 83.31 mm |
| Annual | 4.5 °C | 15.5 °C | 1099.56 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| 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 | Dfb - Humid Continental Mild Summer, Wet All Year |