Ottawa, Ontario climate data is summarized below. Average annual temperatures range from 2.2 °C (low) to 12 °C (high). Annual precipitation averages 382 Millimeters. 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 | -13.37 °C | -4.94 °C | 0 mm |
| February | -13.18 °C | -4 °C | 0 mm |
| March | -6.8 °C | 3.05 °C | 15 mm |
| April | 1.35 °C | 12.29 °C | 34 mm |
| May | 8.39 °C | 20.31 °C | 38 mm |
| June | 13.62 °C | 24.58 °C | 60 mm |
| July | 16.09 °C | 26.89 °C | 72 mm |
| August | 15.18 °C | 25.86 °C | 72 mm |
| September | 10.3 °C | 21.32 °C | 45 mm |
| October | 4.75 °C | 13.64 °C | 28 mm |
| November | -1.5 °C | 6.44 °C | 15 mm |
| December | -8.64 °C | -1.91 °C | 3 mm |
| Annual | 2.2 °C | 12 °C | 382 mm |
| 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 : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |