Farmington, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.7 °C (low) to 15.4 °C (high). Annual precipitation averages 1336.6 Millimeters. Farmington is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.5 °C | 2.2 °C | 108.71 mm |
| February | -6.6 °C | 4.2 °C | 91.69 mm |
| March | -2.8 °C | 8.9 °C | 113.79 mm |
| April | 2.6 °C | 16.1 °C | 114.3 mm |
| May | 8.1 °C | 21.1 °C | 126.75 mm |
| June | 12.7 °C | 24.9 °C | 135.64 mm |
| July | 14.9 °C | 26.8 °C | 130.81 mm |
| August | 14.1 °C | 26.2 °C | 112.78 mm |
| September | 10.1 °C | 22.8 °C | 105.16 mm |
| October | 4.1 °C | 16.6 °C | 94.74 mm |
| November | -1.1 °C | 10.2 °C | 96.01 mm |
| December | -4.7 °C | 4.4 °C | 106.17 mm |
| Annual | 3.7 °C | 15.4 °C | 1336.55 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |