Cornwall, Prince Edward Island climate data is summarized below. Average annual temperatures range from 2.5 °C (low) to 10.5 °C (high). Annual precipitation averages 944 Millimeters. Cornwall is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -10.15 °C | -2.69 °C | 19 mm |
| February | -10.14 °C | -2.35 °C | 7 mm |
| March | -7.13 °C | 0.89 °C | 31 mm |
| April | -0.72 °C | 7.67 °C | 62 mm |
| May | 5.02 °C | 14.25 °C | 86 mm |
| June | 10.19 °C | 19.43 °C | 100 mm |
| July | 15.27 °C | 24.55 °C | 105 mm |
| August | 15.13 °C | 23.88 °C | 125 mm |
| September | 10.89 °C | 19.26 °C | 110 mm |
| October | 5.7 °C | 13.03 °C | 104 mm |
| November | 0.63 °C | 7.05 °C | 102 mm |
| December | -5.34 °C | 1.01 °C | 93 mm |
| Annual | 2.5 °C | 10.5 °C | 944 mm |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |