Bantam, Connecticut has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 38.2 °F (low) to 58.6 °F (high). Annual precipitation averages 51.3 Inches. Bantam is located in USDA Plant Hardiness Zone 6a. 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 | 15.8 °F | 34.1 °F | 3.49 in. |
| February | 17.6 °F | 37.1 °F | 3.0 in. |
| March | 24.7 °F | 45.0 °F | 4.28 in. |
| April | 35.3 °F | 57.9 °F | 3.88 in. |
| May | 45.6 °F | 68.7 °F | 4.15 in. |
| June | 55.0 °F | 76.7 °F | 4.61 in. |
| July | 60.3 °F | 81.5 °F | 4.68 in. |
| August | 59.1 °F | 79.9 °F | 4.89 in. |
| September | 51.9 °F | 72.5 °F | 4.68 in. |
| October | 40.4 °F | 60.9 °F | 5.27 in. |
| November | 30.9 °F | 49.7 °F | 3.89 in. |
| December | 22.2 °F | 38.7 °F | 4.51 in. |
| Annual | 38.2 °F | 58.6 °F | 51.33 in. |
| 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 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |