Star Junction, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.3 °C (low) to 16.4 °C (high). Annual precipitation averages 1115.3 Millimeters. Star Junction 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -6.1 °C | 2.9 °C | 82.04 mm |
| February | -5.5 °C | 4.4 °C | 71.63 mm |
| March | -1.6 °C | 9.7 °C | 89.41 mm |
| April | 4.1 °C | 16.9 °C | 92.71 mm |
| May | 9.8 °C | 22.1 °C | 110.49 mm |
| June | 14.6 °C | 26.3 °C | 116.08 mm |
| July | 17 °C | 28.3 °C | 114.3 mm |
| August | 16.2 °C | 27.9 °C | 97.79 mm |
| September | 12.2 °C | 24.4 °C | 92.71 mm |
| October | 5.9 °C | 17.9 °C | 80.77 mm |
| November | 0.7 °C | 11.1 °C | 82.8 mm |
| December | -3.3 °C | 5.3 °C | 84.58 mm |
| Annual | 5.3 °C | 16.4 °C | 1115.31 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |