Caledon, Ontario climate data is summarized below. Average annual temperatures range from 37.9 °F (low) to 55.4 °F (high). Annual precipitation averages 30.3 Inches. Caledon 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 °F | -18.9 °F | 279.4 in. |
| February | -23.4 °F | -19 °F | 152.4 in. |
| March | -20.3 °F | -15.2 °F | 1066.8 in. |
| April | -16.9 °F | -10.8 °F | 2006.6 in. |
| May | -13.4 °F | -6.7 °F | 2667 in. |
| June | -10.5 °F | -4.2 °F | 2463.8 in. |
| July | -9.1 °F | -2.6 °F | 2616.2 in. |
| August | -9.5 °F | -3.2 °F | 2717.8 in. |
| September | -11.7 °F | -5.6 °F | 1752.6 in. |
| October | -14.7 °F | -9.7 °F | 1676.4 in. |
| November | -18 °F | -13.5 °F | 1244.6 in. |
| December | -20.8 °F | -17.4 °F | 914.4 in. |
| Annual | 37.9 °F | 55.4 °F | 30.32 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 |