Smithville, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 43.3 °F (low) to 64.7 °F (high). Annual precipitation averages 40.1 Inches. Smithville 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 | 18.1 °F | 37.9 °F | 1.17 in. |
| February | 22.1 °F | 43.3 °F | 1.51 in. |
| March | 32.0 °F | 54.7 °F | 2.2 in. |
| April | 42.2 °F | 64.9 °F | 3.86 in. |
| May | 53.4 °F | 74.3 °F | 5.47 in. |
| June | 63.4 °F | 83.7 °F | 5.32 in. |
| July | 67.6 °F | 88.0 °F | 4.88 in. |
| August | 65.2 °F | 86.8 °F | 4.38 in. |
| September | 56.2 °F | 79.2 °F | 4.28 in. |
| October | 44.0 °F | 67.5 °F | 3.41 in. |
| November | 32.3 °F | 53.6 °F | 2.06 in. |
| December | 22.8 °F | 42.0 °F | 1.59 in. |
| Annual | 43.3 °F | 64.7 °F | 40.13 in. |
| Average First Frost Date | Oct. 21 - Oct. 31 |
| Average Last Frost Date | Apr. 11 - Apr. 20 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6a : -10°F to -5°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |