Main Brook, Newfoundland and Labrador climate data is summarized below. Average annual temperatures range from -0.3 °C (low) to 4.9 °C (high). Annual precipitation averages 710 Millimeters. 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 | -10.91 °C | -4.87 °C | 20 mm |
| February | -11.18 °C | -4.84 °C | 14 mm |
| March | -8.46 °C | -2.98 °C | 21 mm |
| April | -3.59 °C | 0.65 °C | 47 mm |
| May | 0.47 °C | 5.44 °C | 62 mm |
| June | 5.4 °C | 11.06 °C | 64 mm |
| July | 10.01 °C | 16.1 °C | 74 mm |
| August | 11.38 °C | 17 °C | 75 mm |
| September | 7.97 °C | 13.1 °C | 98 mm |
| October | 3.48 °C | 7.45 °C | 98 mm |
| November | -1.47 °C | 2.58 °C | 74 mm |
| December | -6.81 °C | -2.06 °C | 63 mm |
| Annual | -0.3 °C | 4.9 °C | 710 mm |
| 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 : -37.2°C to -34.4°C |
| Current Drought Conditions | Normal |