Grindstone, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 5.3 °C (low) to 17.2 °C (high). Annual precipitation averages 1099.3 Millimeters. Grindstone 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 | -5.9 °C | 3.6 °C | 81.28 mm |
| February | -5.3 °C | 5.1 °C | 71.12 mm |
| March | -1.6 °C | 10.4 °C | 90.17 mm |
| April | 3.8 °C | 17.7 °C | 91.19 mm |
| May | 9.6 °C | 22.8 °C | 109.47 mm |
| June | 14.6 °C | 27.1 °C | 114.81 mm |
| July | 16.9 °C | 29.1 °C | 112.78 mm |
| August | 16.2 °C | 28.7 °C | 95.5 mm |
| September | 12.2 °C | 25.3 °C | 89.92 mm |
| October | 5.8 °C | 18.6 °C | 77.98 mm |
| November | 0.5 °C | 11.7 °C | 81.53 mm |
| December | -3.1 °C | 5.9 °C | 83.57 mm |
| Annual | 5.3 °C | 17.2 °C | 1099.32 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 | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |