Ottawa, Ontario climate data is summarized below. Average annual temperatures range from 35.9 °F (low) to 53.5 °F (high). Annual precipitation averages 15 Inches. Ottawa is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -25.2 °F | -20.5 °F | 0 in. |
| February | -25.1 °F | -20 °F | 0 in. |
| March | -21.6 °F | -16.1 °F | 381 in. |
| April | -17 °F | -11 °F | 863.6 in. |
| May | -13.1 °F | -6.5 °F | 965.2 in. |
| June | -10.2 °F | -4.1 °F | 1524 in. |
| July | -8.8 °F | -2.8 °F | 1828.8 in. |
| August | -9.3 °F | -3.4 °F | 1828.8 in. |
| September | -12.1 °F | -5.9 °F | 1143 in. |
| October | -15.1 °F | -10.2 °F | 711.2 in. |
| November | -18.6 °F | -14.2 °F | 381 in. |
| December | -22.6 °F | -18.8 °F | 76.2 in. |
| Annual | 35.9 °F | 53.5 °F | 15.03 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |