Cottage Grove, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36.7 °F (low) to 54.8 °F (high). Annual precipitation averages 33.8 Inches. Cottage Grove is located in USDA Plant Hardiness Zone 5a. The growing season typically runs from the last frost around Apr. 21 - Apr. 30 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 7.1 °F | 23.4 °F | 0.99 in. |
| February | 10.4 °F | 28.2 °F | 0.92 in. |
| March | 22.5 °F | 40.6 °F | 1.67 in. |
| April | 35.8 °F | 55.5 °F | 2.95 in. |
| May | 48.3 °F | 68.0 °F | 4.22 in. |
| June | 58.9 °F | 77.9 °F | 5.15 in. |
| July | 63.5 °F | 82.3 °F | 4.44 in. |
| August | 61.0 °F | 80.0 °F | 4.43 in. |
| September | 52.5 °F | 72.4 °F | 3.31 in. |
| October | 39.5 °F | 58.1 °F | 2.8 in. |
| November | 26.7 °F | 42.2 °F | 1.61 in. |
| December | 14.3 °F | 28.7 °F | 1.29 in. |
| Annual | 36.7 °F | 54.8 °F | 33.78 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | Apr. 21 - Apr. 30 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5a : -20°F to -15°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 |