Forest Lake, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 34.6 °F (low) to 55.3 °F (high). Annual precipitation averages 31.9 Inches. Forest Lake 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 | 5.1 °F | 23.4 °F | 0.83 in. |
| February | 8.4 °F | 28.8 °F | 0.82 in. |
| March | 20.5 °F | 41.4 °F | 1.5 in. |
| April | 33.5 °F | 56.3 °F | 2.83 in. |
| May | 46.2 °F | 69.0 °F | 4.16 in. |
| June | 56.4 °F | 78.3 °F | 4.62 in. |
| July | 61.0 °F | 82.8 °F | 4.43 in. |
| August | 58.5 °F | 80.7 °F | 4.05 in. |
| September | 50.3 °F | 73.0 °F | 3.14 in. |
| October | 37.8 °F | 58.7 °F | 2.76 in. |
| November | 25.1 °F | 42.2 °F | 1.6 in. |
| December | 12.4 °F | 28.6 °F | 1.13 in. |
| Annual | 34.6 °F | 55.3 °F | 31.87 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 | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |