Petrolia, Ontario climate data is summarized below. Average annual temperatures range from 38.5 °F (low) to 57.2 °F (high). Annual precipitation averages 12 Inches. Petrolia 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. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -22.6 °F | -18.4 °F | 203.2 in. |
| February | -23.1 °F | -18.5 °F | 25.4 in. |
| March | -19.8 °F | -14.4 °F | 482.6 in. |
| April | -16.7 °F | -10.1 °F | 762 in. |
| May | -13.3 °F | -6.3 °F | 990.6 in. |
| June | -10.5 °F | -3.5 °F | 889 in. |
| July | -9.1 °F | -2.4 °F | 1016 in. |
| August | -9.5 °F | -2.9 °F | 1270 in. |
| September | -11.9 °F | -5.3 °F | 787.4 in. |
| October | -14.7 °F | -9 °F | 660.4 in. |
| November | -17.8 °F | -13 °F | 457.2 in. |
| December | -20.4 °F | -16.6 °F | 203.2 in. |
| Annual | 38.5 °F | 57.2 °F | 12 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |