Osseo, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 33.7 °F (low) to 54.7 °F (high). Annual precipitation averages 34.2 Inches. Osseo is located in USDA Plant Hardiness Zone 4b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 1 - Oct. 10.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 4.9 °F | 23.7 °F | 1.08 in. |
| February | 8.2 °F | 28.7 °F | 1.04 in. |
| March | 20.3 °F | 41.1 °F | 1.75 in. |
| April | 32.8 °F | 55.4 °F | 3.22 in. |
| May | 44.9 °F | 68.3 °F | 4.21 in. |
| June | 55.2 °F | 77.5 °F | 5.13 in. |
| July | 59.1 °F | 81.6 °F | 3.93 in. |
| August | 56.9 °F | 79.6 °F | 4.23 in. |
| September | 48.5 °F | 71.6 °F | 3.81 in. |
| October | 36.4 °F | 57.7 °F | 2.73 in. |
| November | 24.6 °F | 42.2 °F | 1.72 in. |
| December | 12.4 °F | 28.9 °F | 1.39 in. |
| Annual | 33.7 °F | 54.7 °F | 34.24 in. |
| Average First Frost Date | Oct. 1 - Oct. 10 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 150-180 Days |
| Plant Hardiness Zone | Zone 4b : -25°F to -20°F |
| Plant Hardiness Zone - 2012 | Zone 4b : -25°F to -20°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |