Gratz, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.8 °C (low) to 15.8 °C (high). Annual precipitation averages 1220.2 Millimeters. Gratz 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.1 °C | 2 °C | 71.37 mm |
| February | -6.4 °C | 3.6 °C | 67.82 mm |
| March | -2.1 °C | 8.6 °C | 97.79 mm |
| April | 3.9 °C | 15.7 °C | 103.89 mm |
| May | 9.3 °C | 21.3 °C | 106.68 mm |
| June | 14.2 °C | 25.8 °C | 117.09 mm |
| July | 16.4 °C | 28.4 °C | 118.87 mm |
| August | 15.5 °C | 27.6 °C | 112.78 mm |
| September | 11.6 °C | 23.9 °C | 128.78 mm |
| October | 5.5 °C | 17.2 °C | 112.78 mm |
| November | 0.3 °C | 10.7 °C | 87.63 mm |
| December | -3.9 °C | 4.6 °C | 94.74 mm |
| Annual | 4.8 °C | 15.8 °C | 1220.22 mm |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |