Gilman, Minnesota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from 0.3 °C (low) to 11.7 °C (high). Annual precipitation averages 751.1 Millimeters. Gilman 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 Sep. 21 - Sep. 30.
| Month | Avg. Low | Avg. High | Avg. Precip |
|---|---|---|---|
| January | -16.8 °C | -6.2 °C | 17.02 mm |
| February | -14.7 °C | -3.1 °C | 19.3 mm |
| March | -7.6 °C | 3.9 °C | 34.54 mm |
| April | -0.4 °C | 12.1 °C | 66.04 mm |
| May | 6.9 °C | 19.7 °C | 95.76 mm |
| June | 12.7 °C | 24.8 °C | 113.28 mm |
| July | 15.3 °C | 27.3 °C | 103.12 mm |
| August | 13.9 °C | 26.2 °C | 99.82 mm |
| September | 9.3 °C | 21.7 °C | 72.9 mm |
| October | 2.4 °C | 13.6 °C | 69.85 mm |
| November | -5.2 °C | 4.2 °C | 34.54 mm |
| December | -12.3 °C | -3.3 °C | 24.89 mm |
| Annual | 0.3 °C | 11.7 °C | 751.06 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 4a : -34.4°C to -31.7°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 |