Farnham, Quebec climate data is summarized below. Average annual temperatures range from 2.3 °C (low) to 12.2 °C (high). Annual precipitation averages 482 Millimeters. Farnham is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -12.69 °C | -3.76 °C | 13 mm |
| February | -12.39 °C | -3.34 °C | 13 mm |
| March | -6.58 °C | 3.34 °C | 30 mm |
| April | 1.45 °C | 12.16 °C | 60 mm |
| May | 8.16 °C | 19.75 °C | 53 mm |
| June | 13.23 °C | 23.96 °C | 57 mm |
| July | 15.75 °C | 26.67 °C | 74 mm |
| August | 14.86 °C | 25.69 °C | 48 mm |
| September | 10.14 °C | 21.18 °C | 31 mm |
| October | 4.78 °C | 13.79 °C | 47 mm |
| November | -0.83 °C | 6.95 °C | 35 mm |
| December | -7.88 °C | -0.78 °C | 21 mm |
| Annual | 2.3 °C | 12.2 °C | 482 mm |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 5b : -26.1°C to -23.3°C |
| Current Drought Conditions | Normal |