Richmond, Massachusetts has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 2 °C (low) to 13.7 °C (high). Annual precipitation averages 1220.5 Millimeters. Richmond is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.7 °C | -0.6 °C | 88.14 mm |
| February | -10 °C | 1.1 °C | 71.63 mm |
| March | -5.6 °C | 5.5 °C | 87.88 mm |
| April | 0.3 °C | 13.3 °C | 93.98 mm |
| May | 6.4 °C | 19.9 °C | 97.03 mm |
| June | 11.6 °C | 24.2 °C | 124.21 mm |
| July | 14.3 °C | 26.8 °C | 118.36 mm |
| August | 13.2 °C | 25.8 °C | 117.86 mm |
| September | 9.3 °C | 22 °C | 112.52 mm |
| October | 3.3 °C | 15.1 °C | 118.11 mm |
| November | -1.8 °C | 8.4 °C | 87.63 mm |
| December | -6.7 °C | 2.3 °C | 103.12 mm |
| Annual | 2 °C | 13.7 °C | 1220.47 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |