Flensburg, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Annual precipitation averages 724.4 Millimeters. 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 | -17.2 °C | -6.6 °C | 17.02 mm |
| February | -15.2 °C | -3.7 °C | 18.03 mm |
| March | -7.9 °C | 3.4 °C | 33.53 mm |
| April | -0.6 °C | 11.8 °C | 62.23 mm |
| May | 6.7 °C | 19.4 °C | 89.41 mm |
| June | 12.6 °C | 24.7 °C | 114.55 mm |
| July | 15.2 °C | 27.4 °C | 103.63 mm |
| August | 13.6 °C | 26.1 °C | 89.15 mm |
| September | 8.9 °C | 21.6 °C | 73.41 mm |
| October | 1.9 °C | 13.2 °C | 69.85 mm |
| November | -5.4 °C | 3.9 °C | 30.73 mm |
| December | -12.6 °C | -3.6 °C | 22.86 mm |
| Annual | 0 °C | 11.5 °C | 724.4 mm |
| 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 : -34.4°C to -31.7°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 |