Flensburg, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32 °F (low) to 52.7 °F (high). Annual precipitation averages 28.5 Inches. Flensburg is located in USDA Plant Hardiness Zone 4a. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.0 °F | 20.2 °F | 0.67 in. |
| February | 4.7 °F | 25.4 °F | 0.71 in. |
| March | 17.7 °F | 38.2 °F | 1.32 in. |
| April | 31.0 °F | 53.3 °F | 2.45 in. |
| May | 44.1 °F | 66.9 °F | 3.52 in. |
| June | 54.7 °F | 76.4 °F | 4.51 in. |
| July | 59.3 °F | 81.4 °F | 4.08 in. |
| August | 56.4 °F | 79.0 °F | 3.51 in. |
| September | 48.0 °F | 70.8 °F | 2.89 in. |
| October | 35.4 °F | 55.8 °F | 2.75 in. |
| November | 22.3 °F | 39.0 °F | 1.21 in. |
| December | 9.4 °F | 25.6 °F | 0.9 in. |
| Annual | 32 °F | 52.7 °F | 28.52 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4a : -30°F to -25°F |
| Plant Hardiness Zone - 2012 | Zone 4a : -30°F to -25°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |