Lyndon, Vermont has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.5 °C (low) to 11.9 °C (high). Annual precipitation averages 1027.2 Millimeters. Lyndon is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 11 - May 20 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -15.3 °C | -3.6 °C | 60.2 mm |
| February | -15 °C | -1.7 °C | 55.63 mm |
| March | -9.3 °C | 3.3 °C | 60.45 mm |
| April | -1.6 °C | 11.1 °C | 80.26 mm |
| May | 4.8 °C | 18.7 °C | 104.9 mm |
| June | 10.2 °C | 23.4 °C | 97.03 mm |
| July | 13 °C | 26.1 °C | 111 mm |
| August | 11.9 °C | 25.2 °C | 102.62 mm |
| September | 7.7 °C | 20.9 °C | 92.71 mm |
| October | 1.7 °C | 13.3 °C | 104.39 mm |
| November | -3.7 °C | 6 °C | 70.61 mm |
| December | -10.2 °C | -0.3 °C | 87.38 mm |
| Annual | -0.5 °C | 11.9 °C | 1027.18 mm |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 11 - May 20 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |