Ronneby, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 32.4 °F (low) to 53.1 °F (high). Annual precipitation averages 29.6 Inches. Ronneby 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 Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | 1.9 °F | 20.9 °F | 0.66 in. |
| February | 5.5 °F | 26.3 °F | 0.76 in. |
| March | 18.4 °F | 38.8 °F | 1.41 in. |
| April | 31.5 °F | 53.7 °F | 2.62 in. |
| May | 44.4 °F | 67.3 °F | 3.87 in. |
| June | 54.8 °F | 76.6 °F | 4.3 in. |
| July | 59.3 °F | 80.9 °F | 4.06 in. |
| August | 56.6 °F | 78.9 °F | 3.92 in. |
| September | 48.4 °F | 71.2 °F | 2.93 in. |
| October | 35.8 °F | 56.6 °F | 2.74 in. |
| November | 22.7 °F | 39.7 °F | 1.39 in. |
| December | 10.0 °F | 26.2 °F | 0.97 in. |
| Annual | 32.4 °F | 53.1 °F | 29.63 in. |
| Average First Frost Date | Sep. 21 - Sep. 30 |
| 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 4a : -30°F to -25°F |
| Current Drought Conditions | Abnormally Dry |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |