Siasconset, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 7.5 °C (low) to 13.9 °C (high). Annual precipitation averages 1165.1 Millimeters. Siasconset is located in USDA Plant Hardiness Zone 7b. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -2.9 °C | 4 °C | 104.14 mm |
| February | -2.5 °C | 4.2 °C | 93.47 mm |
| March | 0.2 °C | 6.4 °C | 123.95 mm |
| April | 4.6 °C | 11.1 °C | 108.71 mm |
| May | 9.2 °C | 15.6 °C | 77.72 mm |
| June | 14.1 °C | 20.2 °C | 74.42 mm |
| July | 18.1 °C | 24.1 °C | 65.02 mm |
| August | 18.2 °C | 24.2 °C | 80.77 mm |
| September | 15.4 °C | 21.5 °C | 95.25 mm |
| October | 10.3 °C | 16.4 °C | 115.57 mm |
| November | 5.2 °C | 11.6 °C | 103.63 mm |
| December | 0.4 °C | 7.2 °C | 122.43 mm |
| Annual | 7.5 °C | 13.9 °C | 1165.08 mm |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7b : -15°C to -12.2°C |
| Plant Hardiness Zone - 2012 | Zone 7a : -17.8°C to -15°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |