Walnut Grove, Minnesota has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 34.9 °F (low) to 54.9 °F (high). Annual precipitation averages 29.7 Inches. Walnut Grove is located in USDA Plant Hardiness Zone 5a. 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 | 5.6 °F | 23.2 °F | 0.77 in. |
| February | 9.6 °F | 27.7 °F | 0.78 in. |
| March | 21.6 °F | 39.6 °F | 1.62 in. |
| April | 33.7 °F | 55.2 °F | 2.97 in. |
| May | 46.9 °F | 68.6 °F | 4.02 in. |
| June | 58.1 °F | 78.8 °F | 4.58 in. |
| July | 61.6 °F | 82.3 °F | 3.59 in. |
| August | 58.7 °F | 80.0 °F | 3.48 in. |
| September | 50.0 °F | 73.6 °F | 3.3 in. |
| October | 36.9 °F | 59.3 °F | 2.33 in. |
| November | 24.0 °F | 42.1 °F | 1.33 in. |
| December | 12.2 °F | 28.4 °F | 0.94 in. |
| Annual | 34.9 °F | 54.9 °F | 29.71 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 5a : -20°F to -15°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |