Oil City, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 3.5 °C (low) to 15.4 °C (high). Annual precipitation averages 1184.7 Millimeters. Oil City is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -8.1 °C | 1.3 °C | 85.34 mm |
| February | -7.8 °C | 2.8 °C | 64.52 mm |
| March | -3.9 °C | 7.8 °C | 88.65 mm |
| April | 1.7 °C | 15.3 °C | 104.39 mm |
| May | 7.6 °C | 21.7 °C | 101.85 mm |
| June | 12.8 °C | 26 °C | 130.81 mm |
| July | 15.1 °C | 28.2 °C | 128.27 mm |
| August | 14.4 °C | 27.4 °C | 104.65 mm |
| September | 10.7 °C | 23.6 °C | 103.38 mm |
| October | 4.6 °C | 16.8 °C | 94.23 mm |
| November | -0.5 °C | 9.7 °C | 88.39 mm |
| December | -4.7 °C | 3.7 °C | 90.17 mm |
| Annual | 3.5 °C | 15.4 °C | 1184.65 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -23.3°C to -20.6°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 |