Cornwall, Prince Edward Island climate data is summarized below. Average annual temperatures range from 36.4 °F (low) to 50.9 °F (high). Annual precipitation averages 37.2 Inches. 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 | -23.4 °F | -19.3 °F | 482.6 in. |
| February | -23.4 °F | -19.1 °F | 177.8 in. |
| March | -21.7 °F | -17.3 °F | 787.4 in. |
| April | -18.2 °F | -13.5 °F | 1574.8 in. |
| May | -15 °F | -9.9 °F | 2184.4 in. |
| June | -12.1 °F | -7 °F | 2540 in. |
| July | -9.3 °F | -4.1 °F | 2667 in. |
| August | -9.4 °F | -4.5 °F | 3175 in. |
| September | -11.7 °F | -7.1 °F | 2794 in. |
| October | -14.6 °F | -10.5 °F | 2641.6 in. |
| November | -17.4 °F | -13.9 °F | 2590.8 in. |
| December | -20.7 °F | -17.2 °F | 2362.2 in. |
| Annual | 36.4 °F | 50.9 °F | 37.17 in. |
| 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 : -15°F to -10°F |
| Current Drought Conditions | Normal |