Medway, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 4.1 °C (low) to 15.8 °C (high). Annual precipitation averages 1254.5 Millimeters. Medway is located in USDA Plant Hardiness Zone 6b. 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 | -8.1 °C | 2.5 °C | 99.57 mm |
| February | -7.2 °C | 3.9 °C | 85.85 mm |
| March | -3.1 °C | 8 °C | 116.08 mm |
| April | 2.4 °C | 14.9 °C | 113.54 mm |
| May | 8 °C | 20.6 °C | 89.15 mm |
| June | 13.2 °C | 25.3 °C | 111 mm |
| July | 16.4 °C | 28.4 °C | 89.92 mm |
| August | 15.6 °C | 27.7 °C | 100.84 mm |
| September | 11.3 °C | 23.9 °C | 100.58 mm |
| October | 4.9 °C | 17.3 °C | 124.97 mm |
| November | -0.1 °C | 11.2 °C | 101.85 mm |
| December | -4.7 °C | 5.5 °C | 121.16 mm |
| Annual | 4.1 °C | 15.8 °C | 1254.51 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -20.6°C to -17.8°C |
| Plant Hardiness Zone - 2012 | Zone 6a : -23.3°C to -20.6°C |
| Current Drought Conditions | Severe Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |