Johnstown, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37 °F (low) to 56.1 °F (high). Annual precipitation averages 46.2 Inches. Johnstown is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 12.8 °F | 29.6 °F | 3.29 in. |
| February | 14.3 °F | 32.3 °F | 2.95 in. |
| March | 22.3 °F | 40.6 °F | 3.48 in. |
| April | 34.3 °F | 54.9 °F | 3.91 in. |
| May | 46.0 °F | 68.0 °F | 3.92 in. |
| June | 55.2 °F | 76.2 °F | 4.65 in. |
| July | 60.3 °F | 80.6 °F | 4.51 in. |
| August | 58.4 °F | 79.1 °F | 4.5 in. |
| September | 51.1 °F | 71.9 °F | 3.73 in. |
| October | 39.6 °F | 59.3 °F | 4.34 in. |
| November | 29.6 °F | 45.9 °F | 3.31 in. |
| December | 20.4 °F | 34.7 °F | 3.57 in. |
| Annual | 37 °F | 56.1 °F | 46.16 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5a : -20°F to -15°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |