Altamont, Pennsylvania has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 39 °F (low) to 57.8 °F (high). Annual precipitation averages 52.9 Inches. Altamont is located in USDA Plant Hardiness Zone 6b. 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 | 17.3 °F | 33.1 °F | 3.76 in. |
| February | 18.4 °F | 35.8 °F | 2.97 in. |
| March | 25.7 °F | 44.4 °F | 4.08 in. |
| April | 36.8 °F | 57.6 °F | 4.33 in. |
| May | 47.0 °F | 68.3 °F | 4.54 in. |
| June | 56.0 °F | 75.9 °F | 5.12 in. |
| July | 60.6 °F | 80.7 °F | 4.97 in. |
| August | 58.7 °F | 79.0 °F | 4.61 in. |
| September | 52.0 °F | 72.3 °F | 5.35 in. |
| October | 41.0 °F | 60.8 °F | 5.09 in. |
| November | 31.2 °F | 48.3 °F | 3.86 in. |
| December | 23.1 °F | 37.9 °F | 4.22 in. |
| Annual | 39 °F | 57.8 °F | 52.9 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |