Barnett, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 45.4 °F (low) to 66.1 °F (high). Annual precipitation averages 44 Inches. Barnett is located in USDA Plant Hardiness Zone 6b. The growing season typically runs from the last frost around Apr. 1 - Apr. 10 through the first frost around Nov. 1 - Nov. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 21.9 °F | 40.7 °F | 2.16 in. |
| February | 25.8 °F | 45.8 °F | 2.13 in. |
| March | 34.3 °F | 56.4 °F | 2.98 in. |
| April | 44.4 °F | 67.1 °F | 4.93 in. |
| May | 54.7 °F | 75.4 °F | 5.39 in. |
| June | 63.8 °F | 83.7 °F | 4.7 in. |
| July | 67.9 °F | 87.8 °F | 4.25 in. |
| August | 66.0 °F | 87.2 °F | 3.99 in. |
| September | 57.7 °F | 79.9 °F | 4.46 in. |
| October | 46.4 °F | 69.1 °F | 3.53 in. |
| November | 35.6 °F | 55.3 °F | 3.16 in. |
| December | 26.2 °F | 44.7 °F | 2.32 in. |
| Annual | 45.4 °F | 66.1 °F | 44 in. |
| Average First Frost Date | Nov. 1 - Nov. 10 |
| Average Last Frost Date | Apr. 1 - Apr. 10 |
| Average Days With Frost | 75-100 Days |
| Plant Hardiness Zone | Zone 6b : -5°F to 0°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 |