Exeter, Ontario climate data is summarized below. Average annual temperatures range from 38.4 °F (low) to 55.9 °F (high). Annual precipitation averages 15.4 Inches. Exeter 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -22.6 °F | -18.7 °F | 50.8 in. |
| February | -23.7 °F | -18.9 °F | 0 in. |
| March | -20.4 °F | -15 °F | 482.6 in. |
| April | -16.6 °F | -10.5 °F | 635 in. |
| May | -13.2 °F | -6.5 °F | 1168.4 in. |
| June | -10.4 °F | -4.1 °F | 1752.6 in. |
| July | -9.2 °F | -2.9 °F | 2108.2 in. |
| August | -9.5 °F | -3.2 °F | 1574.8 in. |
| September | -11.7 °F | -5.4 °F | 1092.2 in. |
| October | -14.5 °F | -9.4 °F | 584.2 in. |
| November | -17.6 °F | -13.4 °F | 355.6 in. |
| December | -20.3 °F | -16.9 °F | 127 in. |
| Annual | 38.4 °F | 55.9 °F | 15.4 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |