Knox, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.4 °F (low) to 58.5 °F (high). Annual precipitation averages 46.8 Inches. Knox 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 | 17.0 °F | 33.3 °F | 3.46 in. |
| February | 17.6 °F | 36.0 °F | 2.49 in. |
| March | 24.6 °F | 45.4 °F | 3.42 in. |
| April | 34.8 °F | 58.8 °F | 4.0 in. |
| May | 45.0 °F | 70.0 °F | 3.92 in. |
| June | 53.8 °F | 77.4 °F | 5.26 in. |
| July | 57.8 °F | 80.9 °F | 5.09 in. |
| August | 56.4 °F | 80.2 °F | 4.25 in. |
| September | 49.7 °F | 73.1 °F | 4.2 in. |
| October | 39.3 °F | 60.8 °F | 3.53 in. |
| November | 29.9 °F | 48.4 °F | 3.6 in. |
| December | 23.1 °F | 37.5 °F | 3.56 in. |
| Annual | 37.4 °F | 58.5 °F | 46.78 in. |
| 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 : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |