Cairnbrook, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 38 °F (low) to 56.3 °F (high). Annual precipitation averages 41.9 Inches. Cairnbrook 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 | 17.2 °F | 33.0 °F | 3.04 in. |
| February | 18.4 °F | 35.3 °F | 2.97 in. |
| March | 25.2 °F | 43.5 °F | 3.51 in. |
| April | 36.3 °F | 56.7 °F | 3.31 in. |
| May | 46.1 °F | 66.4 °F | 4.41 in. |
| June | 54.4 °F | 73.9 °F | 4.15 in. |
| July | 58.6 °F | 77.7 °F | 3.88 in. |
| August | 57.1 °F | 76.5 °F | 3.64 in. |
| September | 49.8 °F | 70.2 °F | 3.95 in. |
| October | 39.9 °F | 58.7 °F | 3.19 in. |
| November | 30.2 °F | 47.0 °F | 2.82 in. |
| December | 23.3 °F | 37.2 °F | 3.07 in. |
| Annual | 38 °F | 56.3 °F | 41.94 in. |
| 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 : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |