Oswayo, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 1.3 °C (low) to 13.4 °C (high). Annual precipitation averages 1097.5 Millimeters. Oswayo is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.2 °C | -0.7 °C | 75.95 mm |
| February | -9.8 °C | 0.9 °C | 54.61 mm |
| March | -6.1 °C | 5.7 °C | 72.39 mm |
| April | -0.3 °C | 13.3 °C | 94.23 mm |
| May | 5.6 °C | 20 °C | 95.25 mm |
| June | 10.3 °C | 24 °C | 112.78 mm |
| July | 12.7 °C | 26.1 °C | 113.79 mm |
| August | 11.9 °C | 25.2 °C | 105.92 mm |
| September | 8.2 °C | 21.7 °C | 109.22 mm |
| October | 2.6 °C | 14.9 °C | 102.36 mm |
| November | -2.2 °C | 7.9 °C | 83.82 mm |
| December | -6.6 °C | 1.8 °C | 77.22 mm |
| Annual | 1.3 °C | 13.4 °C | 1097.54 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |