Boston, Indiana has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 4.9 °C (low) to 16 °C (high). Annual precipitation averages 1086.9 Millimeters. Boston is located in USDA Plant Hardiness Zone 6a. 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 | -7.7 °C | 1.4 °C | 77.98 mm |
| February | -6.2 °C | 3.7 °C | 59.18 mm |
| March | -1.7 °C | 9.5 °C | 88.39 mm |
| April | 4 °C | 16.6 °C | 112.27 mm |
| May | 10.3 °C | 21.9 °C | 121.41 mm |
| June | 15.3 °C | 26.6 °C | 118.87 mm |
| July | 16.6 °C | 28.1 °C | 101.35 mm |
| August | 15.5 °C | 27.6 °C | 77.47 mm |
| September | 11.4 °C | 24.4 °C | 77.47 mm |
| October | 5.5 °C | 17.8 °C | 82.55 mm |
| November | 0.2 °C | 10.6 °C | 85.34 mm |
| December | -4.4 °C | 3.9 °C | 84.58 mm |
| Annual | 4.9 °C | 16 °C | 1086.86 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 6a : -23.3°C to -20.6°C |
| Plant Hardiness Zone - 2012 | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |