Lake Lillian, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34.1 °F (low) to 53.8 °F (high). Annual precipitation averages 29.7 Inches. Lake Lillian is located in USDA Plant Hardiness Zone 4b. 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 | 3.7 °F | 21.3 °F | 0.77 in. |
| February | 7.1 °F | 25.9 °F | 0.9 in. |
| March | 20.0 °F | 38.3 °F | 1.54 in. |
| April | 33.4 °F | 54.7 °F | 2.64 in. |
| May | 46.4 °F | 68.2 °F | 3.55 in. |
| June | 57.4 °F | 77.8 °F | 4.82 in. |
| July | 61.2 °F | 81.7 °F | 3.71 in. |
| August | 58.4 °F | 79.4 °F | 3.9 in. |
| September | 49.7 °F | 72.6 °F | 3.11 in. |
| October | 36.7 °F | 57.9 °F | 2.41 in. |
| November | 23.6 °F | 40.7 °F | 1.34 in. |
| December | 11.0 °F | 26.7 °F | 0.99 in. |
| Annual | 34.1 °F | 53.8 °F | 29.68 in. |
| 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 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |