Osborn, Missouri has a Humid Continental Hot Summers With Year Around Precipitation climate (Köppen classification: Dfa). Average annual temperatures range from 42.5 °F (low) to 63.2 °F (high). Annual precipitation averages 39.7 Inches. Osborn 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. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 17.0 °F | 35.4 °F | 1.04 in. |
| February | 20.6 °F | 40.8 °F | 1.43 in. |
| March | 31.4 °F | 52.7 °F | 2.51 in. |
| April | 40.5 °F | 63.8 °F | 3.83 in. |
| May | 52.4 °F | 73.4 °F | 5.68 in. |
| June | 62.5 °F | 82.5 °F | 5.3 in. |
| July | 67.0 °F | 87.3 °F | 4.71 in. |
| August | 64.9 °F | 85.6 °F | 4.39 in. |
| September | 55.5 °F | 78.5 °F | 4.03 in. |
| October | 43.7 °F | 66.1 °F | 3.19 in. |
| November | 32.4 °F | 52.4 °F | 2.0 in. |
| December | 22.4 °F | 39.8 °F | 1.63 in. |
| Annual | 42.5 °F | 63.2 °F | 39.74 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| 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 5b : -15°F to -10°F |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfa - Humid Continental Hot Summers With Year Around Precipitation |