Johnstown, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 39.8 °F (low) to 61.3 °F (high). Annual precipitation averages 48.4 Inches. Johnstown is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 19.7 °F | 36.4 °F | 3.66 in. |
| February | 21.2 °F | 39.4 °F | 3.34 in. |
| March | 27.9 °F | 47.9 °F | 4.07 in. |
| April | 37.8 °F | 62.2 °F | 4.28 in. |
| May | 47.8 °F | 72.1 °F | 4.28 in. |
| June | 56.1 °F | 79.6 °F | 4.61 in. |
| July | 60.0 °F | 83.4 °F | 4.47 in. |
| August | 58.5 °F | 82.1 °F | 4.37 in. |
| September | 51.9 °F | 75.7 °F | 4.34 in. |
| October | 40.7 °F | 64.0 °F | 3.53 in. |
| November | 31.7 °F | 51.4 °F | 3.57 in. |
| December | 24.7 °F | 40.8 °F | 3.86 in. |
| Annual | 39.8 °F | 61.3 °F | 48.38 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |