Zimmerman, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.9 °C (low) to 12.1 °C (high). Annual precipitation averages 796.8 Millimeters. Zimmerman 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 | -15.7 °C | -5.7 °C | 19.56 mm |
| February | -13.9 °C | -2.9 °C | 21.59 mm |
| March | -6.9 °C | 4.2 °C | 40.13 mm |
| April | 0.4 °C | 12.6 °C | 70.36 mm |
| May | 7.5 °C | 19.9 °C | 106.17 mm |
| June | 13.2 °C | 25.2 °C | 109.73 mm |
| July | 15.8 °C | 27.6 °C | 107.7 mm |
| August | 14.2 °C | 26.3 °C | 103.12 mm |
| September | 9.6 °C | 22.2 °C | 80.26 mm |
| October | 2.6 °C | 13.9 °C | 70.1 mm |
| November | -4.4 °C | 4.9 °C | 40.13 mm |
| December | -11.6 °C | -2.8 °C | 27.94 mm |
| Annual | 0.9 °C | 12.1 °C | 796.79 mm |
| 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 : -31.7°C to -28.9°C |
| Plant Hardiness Zone - 2012 | Zone 4a : -34.4°C to -31.7°C |
| Current Drought Conditions | Normal |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |