Sumner, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.6 °F (low) to 63.8 °F (high). Annual precipitation averages 41 Inches. Sumner is located in USDA Plant Hardiness Zone 6a. The growing season typically runs from the last frost around Apr. 11 - Apr. 20 through the first frost around Oct. 21 - Oct. 31.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 16.7 °F | 36.5 °F | 1.33 in. |
| February | 21.3 °F | 41.5 °F | 1.78 in. |
| March | 31.4 °F | 53.3 °F | 2.63 in. |
| April | 42.1 °F | 64.3 °F | 3.95 in. |
| May | 53.1 °F | 73.9 °F | 5.39 in. |
| June | 63.3 °F | 82.9 °F | 5.3 in. |
| July | 67.0 °F | 87.0 °F | 4.87 in. |
| August | 64.3 °F | 85.6 °F | 4.18 in. |
| September | 54.9 °F | 79.6 °F | 4.26 in. |
| October | 43.5 °F | 67.2 °F | 3.23 in. |
| November | 32.1 °F | 53.3 °F | 2.33 in. |
| December | 22.0 °F | 40.6 °F | 1.73 in. |
| Annual | 42.6 °F | 63.8 °F | 40.98 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 100-125 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 6a : -10°F to -5°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |