Dorchester, New Brunswick climate data is summarized below. Average annual temperatures range from 35.7 °F (low) to 51 °F (high). Annual precipitation averages 35.4 Inches. Dorchester is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -23.9 °F | -19.3 °F | 457.2 in. |
| February | -23.7 °F | -18.9 °F | 101.6 in. |
| March | -21.7 °F | -16.8 °F | 660.4 in. |
| April | -17.9 °F | -13.1 °F | 1651 in. |
| May | -14.9 °F | -9.6 °F | 2032 in. |
| June | -12.1 °F | -7.1 °F | 2844.8 in. |
| July | -9.8 °F | -4.8 °F | 2616.2 in. |
| August | -9.8 °F | -4.9 °F | 2692.4 in. |
| September | -12.1 °F | -7.1 °F | 2590.8 in. |
| October | -14.9 °F | -10.3 °F | 2489.2 in. |
| November | -17.8 °F | -13.7 °F | 2438.4 in. |
| December | -21.2 °F | -17.2 °F | 2235.2 in. |
| Annual | 35.7 °F | 51 °F | 35.36 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Abnormally Dry |