McAdam, New Brunswick climate data is summarized below. Average annual temperatures range from 0.3 °C (low) to 11 °C (high). Annual precipitation averages 881 Millimeters. McAdam is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -14.07 °C | -3.93 °C | 12 mm |
| February | -13.27 °C | -2.82 °C | 16 mm |
| March | -8.54 °C | 2.16 °C | 58 mm |
| April | -1.37 °C | 9.78 °C | 84 mm |
| May | 4.96 °C | 16.75 °C | 90 mm |
| June | 9.98 °C | 21.31 °C | 84 mm |
| July | 13.85 °C | 25.34 °C | 86 mm |
| August | 12.91 °C | 24.75 °C | 78 mm |
| September | 8.16 °C | 20.09 °C | 86 mm |
| October | 2.98 °C | 13.02 °C | 111 mm |
| November | -2.39 °C | 6.14 °C | 103 mm |
| December | -9.24 °C | -0.84 °C | 73 mm |
| Annual | 0.3 °C | 11 °C | 881 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5a : -28.9°C to -26.1°C |
| Current Drought Conditions | Moderate Drought |