Carnegie, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.3 °F (low) to 62.5 °F (high). Annual precipitation averages 41.4 Inches. Carnegie is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 22.4 °F | 38.0 °F | 3.24 in. |
| February | 23.8 °F | 40.3 °F | 2.59 in. |
| March | 30.7 °F | 49.5 °F | 3.32 in. |
| April | 40.8 °F | 63.2 °F | 3.49 in. |
| May | 51.2 °F | 72.8 °F | 4.0 in. |
| June | 60.0 °F | 81.0 °F | 4.2 in. |
| July | 64.2 °F | 85.0 °F | 4.37 in. |
| August | 63.0 °F | 83.6 °F | 3.42 in. |
| September | 56.2 °F | 77.1 °F | 3.49 in. |
| October | 44.7 °F | 64.7 °F | 3.05 in. |
| November | 35.0 °F | 52.3 °F | 2.98 in. |
| December | 27.8 °F | 42.2 °F | 3.23 in. |
| Annual | 43.3 °F | 62.5 °F | 41.38 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |