Ontario, New York has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 39.8 °F (low) to 57.7 °F (high). Annual precipitation averages 37.1 Inches. Ontario is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 17.9 °F | 33.2 °F | 2.76 in. |
| February | 18.9 °F | 34.5 °F | 2.17 in. |
| March | 25.5 °F | 42.6 °F | 2.59 in. |
| April | 35.8 °F | 55.4 °F | 3.03 in. |
| May | 46.5 °F | 68.1 °F | 3.09 in. |
| June | 56.3 °F | 75.7 °F | 3.41 in. |
| July | 62.0 °F | 81.2 °F | 3.53 in. |
| August | 60.6 °F | 79.9 °F | 3.43 in. |
| September | 53.9 °F | 73.6 °F | 3.31 in. |
| October | 42.9 °F | 60.5 °F | 3.76 in. |
| November | 33.2 °F | 49.0 °F | 3.05 in. |
| December | 24.5 °F | 38.1 °F | 2.99 in. |
| Annual | 39.8 °F | 57.7 °F | 37.12 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |