Caledon, Ontario climate data is summarized below. Average annual temperatures range from 3.3 °C (low) to 13 °C (high). Annual precipitation averages 770 Millimeters. 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 | -9.33 °C | -1.98 °C | 11 mm |
| February | -10.13 °C | -2.21 °C | 6 mm |
| March | -4.53 °C | 4.7 °C | 42 mm |
| April | 1.54 °C | 12.54 °C | 79 mm |
| May | 7.82 °C | 19.94 °C | 105 mm |
| June | 13.02 °C | 24.51 °C | 97 mm |
| July | 15.66 °C | 27.26 °C | 103 mm |
| August | 14.96 °C | 26.29 °C | 107 mm |
| September | 10.91 °C | 21.92 °C | 69 mm |
| October | 5.46 °C | 14.55 °C | 66 mm |
| November | -0.31 °C | 7.68 °C | 49 mm |
| December | -5.37 °C | 0.67 °C | 36 mm |
| Annual | 3.3 °C | 13 °C | 770 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 |