Trommald, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.6 °C (low) to 10.7 °C (high). Annual precipitation averages 745.5 Millimeters. Trommald is located in USDA Plant Hardiness Zone 4a. 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 | -17.9 °C | -7.3 °C | 20.32 mm |
| February | -16.3 °C | -4.2 °C | 21.08 mm |
| March | -8.9 °C | 3.1 °C | 36.83 mm |
| April | -0.9 °C | 10.9 °C | 58.17 mm |
| May | 6.4 °C | 18.4 °C | 87.88 mm |
| June | 12.2 °C | 23.8 °C | 110.24 mm |
| July | 14.4 °C | 26.4 °C | 114.05 mm |
| August | 12.8 °C | 25.2 °C | 90.93 mm |
| September | 8.2 °C | 20.5 °C | 74.93 mm |
| October | 1.5 °C | 12.3 °C | 71.37 mm |
| November | -5.6 °C | 3.3 °C | 35.05 mm |
| December | -12.8 °C | -4.1 °C | 24.64 mm |
| Annual | -0.6 °C | 10.7 °C | 745.49 mm |
| 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 4a : -34.4°C to -31.7°C |
| Plant Hardiness Zone - 2012 | Zone 3b : -37.2°C to -34.4°C |
| Current Drought Conditions | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |