Mifflinville, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 41.1 °F (low) to 62.2 °F (high). Annual precipitation averages 43.8 Inches. Mifflinville is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 20.2 °F | 36.5 °F | 2.94 in. |
| February | 21.5 °F | 39.4 °F | 2.3 in. |
| March | 28.6 °F | 48.7 °F | 3.07 in. |
| April | 38.4 °F | 62.7 °F | 3.83 in. |
| May | 48.7 °F | 73.4 °F | 3.84 in. |
| June | 58.0 °F | 81.3 °F | 4.62 in. |
| July | 62.4 °F | 85.9 °F | 4.48 in. |
| August | 60.8 °F | 84.0 °F | 4.1 in. |
| September | 53.4 °F | 77.1 °F | 4.77 in. |
| October | 42.0 °F | 64.7 °F | 3.8 in. |
| November | 33.0 °F | 51.9 °F | 2.96 in. |
| December | 25.6 °F | 41.3 °F | 3.13 in. |
| Annual | 41.1 °F | 62.2 °F | 43.84 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |