Walnut, Kansas has a Humid Subtropical Climate climate (Köppen classification: Cfa). Average annual temperatures range from 46.4 °F (low) to 67.6 °F (high). Annual precipitation averages 44.6 Inches. Walnut is located in USDA Plant Hardiness Zone 7a. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 22.9 °F | 42.8 °F | 1.56 in. |
| February | 26.5 °F | 47.7 °F | 1.67 in. |
| March | 35.5 °F | 57.9 °F | 2.92 in. |
| April | 45.2 °F | 67.6 °F | 4.68 in. |
| May | 56.0 °F | 75.9 °F | 6.44 in. |
| June | 65.4 °F | 85.0 °F | 5.56 in. |
| July | 69.7 °F | 89.8 °F | 4.6 in. |
| August | 67.5 °F | 89.4 °F | 4.02 in. |
| September | 59.0 °F | 81.5 °F | 4.58 in. |
| October | 46.8 °F | 70.2 °F | 3.67 in. |
| November | 35.7 °F | 57.2 °F | 2.74 in. |
| December | 26.6 °F | 46.0 °F | 2.17 in. |
| Annual | 46.4 °F | 67.6 °F | 44.61 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 7a : 0°F to 5°F |
| Plant Hardiness Zone - 2012 | Zone 6b : -5°F to 0°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Cfa - Humid Subtropical Climate |