Guelph, Ontario climate data is summarized below. Average annual temperatures range from 37.1 °F (low) to 54.8 °F (high). Annual precipitation averages 33.7 Inches. Guelph is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -23.1 °F | -19.1 °F | 304.8 in. |
| February | -23.9 °F | -19.2 °F | 304.8 in. |
| March | -20.7 °F | -15.3 °F | 1168.4 in. |
| April | -17.1 °F | -11 °F | 2082.8 in. |
| May | -13.6 °F | -7 °F | 2794 in. |
| June | -10.8 °F | -4.4 °F | 2819.4 in. |
| July | -9.5 °F | -3 °F | 3124.2 in. |
| August | -9.9 °F | -3.4 °F | 2946.4 in. |
| September | -12.1 °F | -5.8 °F | 2108.2 in. |
| October | -15 °F | -9.8 °F | 1828.8 in. |
| November | -18.2 °F | -13.6 °F | 1244.6 in. |
| December | -20.8 °F | -17.4 °F | 1016 in. |
| Annual | 37.1 °F | 54.8 °F | 33.69 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |