Bristol, Pennsylvania has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46 °F (low) to 64.8 °F (high). Annual precipitation averages 47 Inches. Bristol is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 25.2 °F | 41.3 °F | 3.54 in. |
| February | 26.3 °F | 44.0 °F | 2.69 in. |
| March | 33.4 °F | 51.8 °F | 4.36 in. |
| April | 43.3 °F | 63.9 °F | 3.48 in. |
| May | 53.0 °F | 73.4 °F | 3.93 in. |
| June | 62.6 °F | 82.5 °F | 4.25 in. |
| July | 68.0 °F | 87.1 °F | 4.8 in. |
| August | 66.2 °F | 85.5 °F | 4.85 in. |
| September | 59.1 °F | 79.0 °F | 3.86 in. |
| October | 47.5 °F | 67.1 °F | 3.84 in. |
| November | 37.4 °F | 56.2 °F | 3.14 in. |
| December | 30.2 °F | 46.1 °F | 4.27 in. |
| Annual | 46 °F | 64.8 °F | 47.01 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 7b : 5°F to 10°F |
| Plant Hardiness Zone - 2012 | Zone 7a : 0°F to 5°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |