New Hamburg, Ontario climate data is summarized below. Average annual temperatures range from 2.5 °C (low) to 12 °C (high). Annual precipitation averages 486 Millimeters. New Hamburg 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 | -9.84 °C | -2.83 °C | 0 mm |
| February | -11.38 °C | -3.16 °C | 0 mm |
| March | -5.41 °C | 3.93 °C | 24 mm |
| April | 0.95 °C | 11.71 °C | 36 mm |
| May | 7.29 °C | 18.87 °C | 54 mm |
| June | 12.31 °C | 23.56 °C | 75 mm |
| July | 14.22 °C | 25.64 °C | 99 mm |
| August | 13.71 °C | 24.58 °C | 85 mm |
| September | 9.71 °C | 20.55 °C | 56 mm |
| October | 4.78 °C | 13.73 °C | 30 mm |
| November | -0.8 °C | 6.71 °C | 18 mm |
| December | -5.54 °C | 0.24 °C | 9 mm |
| Annual | 2.5 °C | 12 °C | 486 mm |
| 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 : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |