Jonestown, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.6 °C (low) to 16.2 °C (high). Annual precipitation averages 1176.3 Millimeters. Jonestown 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 | -6.1 °C | 2.9 °C | 82.55 mm |
| February | -5.4 °C | 4.5 °C | 64.77 mm |
| March | -1.1 °C | 9.5 °C | 97.28 mm |
| April | 4.7 °C | 16.7 °C | 96.52 mm |
| May | 10.2 °C | 22.2 °C | 98.55 mm |
| June | 15.4 °C | 27.1 °C | 117.09 mm |
| July | 17.8 °C | 29.7 °C | 117.35 mm |
| August | 16.8 °C | 28.6 °C | 106.43 mm |
| September | 12.8 °C | 24.8 °C | 123.19 mm |
| October | 6.4 °C | 18.1 °C | 107.95 mm |
| November | 0.9 °C | 11.6 °C | 83.82 mm |
| December | -3.2 °C | 5.5 °C | 93.98 mm |
| Annual | 5.8 °C | 16.8 °C | 1189.48 mm |
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -7.3 °C | 2.2 °C | 81.28 mm |
| February | -6.4 °C | 3.7 °C | 61.72 mm |
| March | -2.4 °C | 8.5 °C | 83.31 mm |
| April | 3.2 °C | 16.2 °C | 100.33 mm |
| May | 8.9 °C | 22.3 °C | 105.92 mm |
| June | 14.1 °C | 26.6 °C | 118.36 mm |
| July | 16.4 °C | 29.1 °C | 119.38 mm |
| August | 15.6 °C | 28.1 °C | 113.54 mm |
| September | 11.6 °C | 24.3 °C | 122.68 mm |
| October | 5.3 °C | 17.6 °C | 102.87 mm |
| November | 0.2 °C | 10.7 °C | 80.26 mm |
| December | -3.9 °C | 4.8 °C | 86.61 mm |
| Annual | 4.6 °C | 16.2 °C | 1176.26 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 7a : -17.8°C to -15°C |
| Plant Hardiness Zone - 2012 | Zone 6b : -20.6°C to -17.8°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |
| 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 : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |