Geraldton, Ontario climate data is summarized below. Average annual temperatures range from -4.1 °C (low) to 6.6 °C (high). Annual precipitation averages 589 Millimeters. Geraldton is located in USDA Plant Hardiness Zone 2b. The growing season typically runs from the last frost around May 21 - May 31 through the first frost around Sep.11 - Sep. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -22.52 °C | -11.71 °C | 0 mm |
| February | -23.04 °C | -9.96 °C | 0 mm |
| March | -14.79 °C | -1.42 °C | 0 mm |
| April | -5.75 °C | 6.08 °C | 9 mm |
| May | 2.43 °C | 14.61 °C | 94 mm |
| June | 8.82 °C | 20.54 °C | 116 mm |
| July | 12.14 °C | 22.81 °C | 108 mm |
| August | 11.46 °C | 22.21 °C | 95 mm |
| September | 6.3 °C | 16.64 °C | 94 mm |
| October | 0.8 °C | 8.53 °C | 71 mm |
| November | -6.89 °C | 0.45 °C | 2 mm |
| December | -18.03 °C | -9.03 °C | 0 mm |
| Annual | -4.1 °C | 6.6 °C | 589 mm |
| Average First Frost Date | Sep.11 - Sep. 20 |
| Average Last Frost Date | May 21 - May 31 |
| Average Days With Frost | Over 180 Days |
| Plant Hardiness Zone | Zone 2b : -42.8°C to -40°C |
| Current Drought Conditions | Normal |