Mount Jewett, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 35.3 °F (low) to 54 °F (high). Annual precipitation averages 50.1 Inches. Mount Jewett is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 14.2 °F | 29.2 °F | 3.99 in. |
| February | 14.6 °F | 31.6 °F | 2.86 in. |
| March | 22.1 °F | 40.4 °F | 3.7 in. |
| April | 33.2 °F | 54.1 °F | 4.4 in. |
| May | 43.5 °F | 65.6 °F | 4.38 in. |
| June | 51.5 °F | 72.8 °F | 4.74 in. |
| July | 55.4 °F | 76.4 °F | 4.82 in. |
| August | 53.9 °F | 74.8 °F | 4.6 in. |
| September | 47.9 °F | 68.4 °F | 4.17 in. |
| October | 37.6 °F | 56.5 °F | 4.31 in. |
| November | 29.2 °F | 44.3 °F | 4.08 in. |
| December | 20.7 °F | 33.9 °F | 4.06 in. |
| Annual | 35.3 °F | 54 °F | 50.11 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| 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 |