Clarion, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.3 °F (low) to 58.4 °F (high). Annual precipitation averages 46.9 Inches. Clarion 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. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.9 °F | 33.1 °F | 3.57 in. |
| February | 17.5 °F | 35.9 °F | 2.57 in. |
| March | 24.5 °F | 45.3 °F | 3.37 in. |
| April | 34.8 °F | 58.8 °F | 3.98 in. |
| May | 44.7 °F | 69.9 °F | 3.86 in. |
| June | 53.5 °F | 77.2 °F | 5.13 in. |
| July | 57.5 °F | 80.8 °F | 5.14 in. |
| August | 56.2 °F | 80.0 °F | 4.24 in. |
| September | 49.5 °F | 73.0 °F | 4.15 in. |
| October | 39.3 °F | 60.8 °F | 3.56 in. |
| November | 29.7 °F | 48.3 °F | 3.73 in. |
| December | 23.0 °F | 37.4 °F | 3.61 in. |
| Annual | 37.3 °F | 58.4 °F | 46.91 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| 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 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |