Oostburg, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 37.9 °F (low) to 54.3 °F (high). Annual precipitation averages 33.1 Inches. Oostburg is located in USDA Plant Hardiness Zone 5b. The growing season typically runs from the last frost around May 1 - May 10 through the first frost around Oct. 11 - Oct. 20.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 13.4 °F | 27.6 °F | 1.62 in. |
| February | 15.9 °F | 30.7 °F | 1.41 in. |
| March | 24.8 °F | 40.4 °F | 2.01 in. |
| April | 34.7 °F | 51.7 °F | 3.67 in. |
| May | 44.7 °F | 63.1 °F | 3.89 in. |
| June | 54.8 °F | 73.5 °F | 3.76 in. |
| July | 61.0 °F | 79.5 °F | 3.56 in. |
| August | 60.5 °F | 77.8 °F | 3.49 in. |
| September | 53.1 °F | 71.0 °F | 2.6 in. |
| October | 41.6 °F | 58.3 °F | 2.91 in. |
| November | 30.3 °F | 44.9 °F | 2.21 in. |
| December | 19.7 °F | 33.4 °F | 1.95 in. |
| Annual | 37.9 °F | 54.3 °F | 33.08 in. |
| Average First Frost Date | Oct. 11 - Oct. 20 |
| Average Last Frost Date | May 1 - May 10 |
| Average Days With Frost | 125-150 Days |
| Plant Hardiness Zone | Zone 5b : -15°F to -10°F |
| Plant Hardiness Zone - 2012 | Zone 5b : -15°F to -10°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |