Ephraim, Wisconsin has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 36.9 °F (low) to 52.4 °F (high). Annual precipitation averages 30.9 Inches. Ephraim 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 | 12.6 °F | 25.8 °F | 1.76 in. |
| February | 13.0 °F | 28.2 °F | 1.0 in. |
| March | 21.8 °F | 37.8 °F | 1.67 in. |
| April | 32.7 °F | 49.3 °F | 2.8 in. |
| May | 43.7 °F | 62.2 °F | 3.44 in. |
| June | 54.1 °F | 72.2 °F | 3.33 in. |
| July | 59.6 °F | 77.4 °F | 2.94 in. |
| August | 59.8 °F | 76.2 °F | 3.19 in. |
| September | 52.4 °F | 68.7 °F | 3.36 in. |
| October | 41.8 °F | 55.8 °F | 3.4 in. |
| November | 31.0 °F | 42.9 °F | 2.29 in. |
| December | 20.8 °F | 31.8 °F | 1.69 in. |
| Annual | 36.9 °F | 52.4 °F | 30.87 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 | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |