Coeymans, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.6 °C (low) to 14.8 °C (high). Annual precipitation averages 1065.5 Millimeters. Coeymans 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 Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -9.3 °C | 0.5 °C | 66.55 mm |
| February | -8.6 °C | 2.1 °C | 57.15 mm |
| March | -4 °C | 6.8 °C | 81.28 mm |
| April | 2.2 °C | 14.6 °C | 89.15 mm |
| May | 8.3 °C | 21.1 °C | 85.09 mm |
| June | 13.4 °C | 25.4 °C | 112.27 mm |
| July | 16.1 °C | 27.9 °C | 99.82 mm |
| August | 15.2 °C | 26.9 °C | 107.95 mm |
| September | 10.8 °C | 23.1 °C | 95.5 mm |
| October | 4.7 °C | 16 °C | 110.24 mm |
| November | -0.6 °C | 9.3 °C | 74.17 mm |
| December | -5.3 °C | 3.3 °C | 86.36 mm |
| Annual | 3.6 °C | 14.8 °C | 1065.53 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 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 | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |