Arnot, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2 °C (low) to 13.6 °C (high). Annual precipitation averages 1022.4 Millimeters. Arnot is located in USDA Plant Hardiness Zone 6a. 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 | -9.7 °C | -0.3 °C | 70.87 mm |
| February | -9.4 °C | 1.1 °C | 54.61 mm |
| March | -5.4 °C | 5.7 °C | 75.44 mm |
| April | 0.3 °C | 13.4 °C | 89.15 mm |
| May | 6.7 °C | 19.8 °C | 87.12 mm |
| June | 11.4 °C | 24.1 °C | 100.58 mm |
| July | 13.7 °C | 26.5 °C | 100.33 mm |
| August | 12.8 °C | 25.6 °C | 93.47 mm |
| September | 8.8 °C | 21.8 °C | 107.7 mm |
| October | 2.9 °C | 15.2 °C | 95.76 mm |
| November | -1.6 °C | 8.1 °C | 72.64 mm |
| December | -6.1 °C | 2.1 °C | 74.68 mm |
| Annual | 2 °C | 13.6 °C | 1022.35 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| 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 |