Main Brook, Newfoundland and Labrador climate data is summarized below. Average annual temperatures range from 31.4 °F (low) to 40.8 °F (high). Annual precipitation averages 28 Inches. Main Brook is located in USDA Plant Hardiness Zone 3b. 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 | -23.8 °F | -20.5 °F | 508 in. |
| February | -24 °F | -20.5 °F | 355.6 in. |
| March | -22.5 °F | -19.4 °F | 533.4 in. |
| April | -19.8 °F | -17.4 °F | 1193.8 in. |
| May | -17.5 °F | -14.8 °F | 1574.8 in. |
| June | -14.8 °F | -11.6 °F | 1625.6 in. |
| July | -12.2 °F | -8.8 °F | 1879.6 in. |
| August | -11.5 °F | -8.3 °F | 1905 in. |
| September | -13.4 °F | -10.5 °F | 2489.2 in. |
| October | -15.8 °F | -13.6 °F | 2489.2 in. |
| November | -18.6 °F | -16.3 °F | 1879.6 in. |
| December | -21.6 °F | -18.9 °F | 1600.2 in. |
| Annual | 31.4 °F | 40.8 °F | 27.95 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 3b : -35°F to -30°F |
| Current Drought Conditions | Normal |