Long Prairie, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.1 °C (low) to 11.1 °C (high). Annual precipitation averages 736.8 Millimeters. Long Prairie 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 | -17.3 °C | -6.9 °C | 19.81 mm |
| February | -15.2 °C | -4 °C | 19.05 mm |
| March | -8.1 °C | 2.9 °C | 35.05 mm |
| April | -0.6 °C | 11.6 °C | 62.48 mm |
| May | 6.8 °C | 19.1 °C | 86.61 mm |
| June | 12.8 °C | 24.4 °C | 114.81 mm |
| July | 15.1 °C | 26.9 °C | 108.97 mm |
| August | 13.5 °C | 25.8 °C | 87.12 mm |
| September | 8.9 °C | 21.3 °C | 76.2 mm |
| October | 1.7 °C | 12.8 °C | 71.37 mm |
| November | -5.6 °C | 3.6 °C | 30.99 mm |
| December | -12.8 °C | -3.9 °C | 24.38 mm |
| Annual | -0.1 °C | 11.1 °C | 736.84 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 |