Marianne, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3 °C (low) to 14.6 °C (high). Annual precipitation averages 1189.2 Millimeters. Marianne 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. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.4 °C | 0.6 °C | 89.92 mm |
| February | -8.1 °C | 2.1 °C | 65.02 mm |
| March | -4.2 °C | 7.3 °C | 85.85 mm |
| April | 1.6 °C | 14.7 °C | 101.09 mm |
| May | 7.2 °C | 20.9 °C | 98.3 mm |
| June | 12.1 °C | 25 °C | 130.56 mm |
| July | 14.2 °C | 27.1 °C | 130.05 mm |
| August | 13.5 °C | 26.6 °C | 107.44 mm |
| September | 9.8 °C | 22.6 °C | 105.41 mm |
| October | 4.1 °C | 15.9 °C | 90.42 mm |
| November | -1.2 °C | 9.1 °C | 93.73 mm |
| December | -5 °C | 3 °C | 91.44 mm |
| Annual | 3 °C | 14.6 °C | 1189.23 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |