Milton, Ontario climate data is summarized below. Average annual temperatures range from 4.4 °C (low) to 13.5 °C (high). Annual precipitation averages 908 Millimeters. Milton 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 | -8.15 °C | -1.17 °C | 19 mm |
| February | -9.42 °C | -1.51 °C | 28 mm |
| March | -3.63 °C | 5.17 °C | 72 mm |
| April | 2.7 °C | 12.64 °C | 99 mm |
| May | 8.93 °C | 19.8 °C | 103 mm |
| June | 14.22 °C | 24.69 °C | 97 mm |
| July | 16.95 °C | 27.71 °C | 95 mm |
| August | 16.39 °C | 26.85 °C | 104 mm |
| September | 12.07 °C | 22.52 °C | 82 mm |
| October | 6.45 °C | 15.13 °C | 79 mm |
| November | 0.62 °C | 8.34 °C | 69 mm |
| December | -4.32 °C | 1.65 °C | 61 mm |
| Annual | 4.4 °C | 13.5 °C | 908 mm |
| 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 : -23.3°C to -20.6°C |
| Current Drought Conditions | Normal |