Harrietstown, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.7 °C (low) to 11.3 °C (high). Annual precipitation averages 1184.9 Millimeters. Harrietstown is located in USDA Plant Hardiness Zone 4a. 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 | -14.7 °C | -3.3 °C | 84.84 mm |
| February | -13.9 °C | -1.7 °C | 64.77 mm |
| March | -9.3 °C | 3 °C | 77.98 mm |
| April | -2 °C | 10.3 °C | 93.73 mm |
| May | 4.3 °C | 17.7 °C | 103.63 mm |
| June | 9.6 °C | 22.6 °C | 122.94 mm |
| July | 12.2 °C | 24.8 °C | 115.57 mm |
| August | 11.2 °C | 23.9 °C | 109.73 mm |
| September | 7.1 °C | 20.3 °C | 102.87 mm |
| October | 1.7 °C | 12.6 °C | 121.92 mm |
| November | -3.9 °C | 5.6 °C | 95.5 mm |
| December | -10.4 °C | -0.4 °C | 91.44 mm |
| Annual | -0.7 °C | 11.3 °C | 1184.92 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |