Belmont, Massachusetts has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 40.7 °F (low) to 60.1 °F (high). Annual precipitation averages 49.6 Inches. Belmont is located in USDA Plant Hardiness Zone 6b. 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 | 18.5 °F | 36.3 °F | 3.95 in. |
| February | 20.2 °F | 38.8 °F | 3.58 in. |
| March | 27.5 °F | 45.9 °F | 4.78 in. |
| April | 37.8 °F | 58.0 °F | 4.3 in. |
| May | 47.7 °F | 68.4 °F | 3.69 in. |
| June | 57.1 °F | 77.4 °F | 4.21 in. |
| July | 63.0 °F | 83.2 °F | 3.74 in. |
| August | 61.5 °F | 81.7 °F | 3.84 in. |
| September | 54.0 °F | 74.6 °F | 3.81 in. |
| October | 42.7 °F | 62.7 °F | 4.82 in. |
| November | 33.3 °F | 52.1 °F | 4.04 in. |
| December | 24.9 °F | 41.9 °F | 4.86 in. |
| Annual | 40.7 °F | 60.1 °F | 49.62 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |