Petrolia, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.9 °F (low) to 60.8 °F (high). Annual precipitation averages 44.4 Inches. Petrolia is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.2 °F | 34.9 °F | 3.31 in. |
| February | 19.2 °F | 38.0 °F | 2.59 in. |
| March | 26.2 °F | 47.3 °F | 3.31 in. |
| April | 36.3 °F | 62.0 °F | 3.95 in. |
| May | 46.7 °F | 72.4 °F | 3.78 in. |
| June | 55.6 °F | 79.9 °F | 5.1 in. |
| July | 59.4 °F | 83.4 °F | 4.55 in. |
| August | 58.0 °F | 82.6 °F | 3.82 in. |
| September | 51.1 °F | 76.1 °F | 4.06 in. |
| October | 40.4 °F | 63.8 °F | 3.26 in. |
| November | 31.5 °F | 50.2 °F | 3.29 in. |
| December | 24.1 °F | 39.3 °F | 3.4 in. |
| Annual | 38.9 °F | 60.8 °F | 44.42 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |