Westmont, Pennsylvania has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 39.6 °F (low) to 58.8 °F (high). Annual precipitation averages 49 Inches. Westmont is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 18.3 °F | 34.3 °F | 3.71 in. |
| February | 19.7 °F | 37.2 °F | 3.36 in. |
| March | 26.3 °F | 45.8 °F | 4.12 in. |
| April | 37.8 °F | 59.6 °F | 4.33 in. |
| May | 47.8 °F | 69.4 °F | 4.38 in. |
| June | 56.4 °F | 76.9 °F | 4.69 in. |
| July | 60.2 °F | 80.7 °F | 4.55 in. |
| August | 58.9 °F | 79.4 °F | 4.41 in. |
| September | 52.3 °F | 73.0 °F | 4.38 in. |
| October | 41.4 °F | 61.3 °F | 3.58 in. |
| November | 31.5 °F | 49.3 °F | 3.61 in. |
| December | 24.3 °F | 38.6 °F | 3.9 in. |
| Annual | 39.6 °F | 58.8 °F | 49.02 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |