Foster Brook, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35 °F (low) to 57 °F (high). Annual precipitation averages 45.2 Inches. Foster Brook is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.0 °F | 31.7 °F | 3.09 in. |
| February | 14.4 °F | 34.1 °F | 2.56 in. |
| March | 21.1 °F | 43.0 °F | 3.02 in. |
| April | 31.6 °F | 56.3 °F | 3.84 in. |
| May | 42.5 °F | 68.7 °F | 4.07 in. |
| June | 51.5 °F | 76.4 °F | 4.42 in. |
| July | 55.7 °F | 80.1 °F | 4.77 in. |
| August | 54.6 °F | 78.5 °F | 4.33 in. |
| September | 47.9 °F | 72.0 °F | 3.99 in. |
| October | 37.1 °F | 59.8 °F | 4.07 in. |
| November | 28.9 °F | 47.1 °F | 3.48 in. |
| December | 20.9 °F | 36.5 °F | 3.57 in. |
| Annual | 35 °F | 57 °F | 45.21 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |