Leonard, North Dakota has a Humid Continental Mild Summer, Wet All Year climate (Köppen classification: Dfb). Average annual temperatures range from -0.3 °C (low) to 11.2 °C (high). Annual precipitation averages 600.7 Millimeters. Leonard 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 | -17.8 °C | -7.8 °C | 15.24 mm |
| February | -15.6 °C | -4.9 °C | 15.24 mm |
| March | -8.3 °C | 2.2 °C | 24.89 mm |
| April | -0.4 °C | 11.8 °C | 35.05 mm |
| May | 6.9 °C | 19.7 °C | 78.74 mm |
| June | 13.2 °C | 24.9 °C | 110.24 mm |
| July | 15.2 °C | 27.3 °C | 85.6 mm |
| August | 13.6 °C | 26.7 °C | 69.6 mm |
| September | 8.4 °C | 22.1 °C | 70.61 mm |
| October | 1.4 °C | 13.4 °C | 57.4 mm |
| November | -6.5 °C | 3.8 °C | 19.56 mm |
| December | -13.4 °C | -4.3 °C | 18.54 mm |
| Annual | -0.3 °C | 11.2 °C | 600.71 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 | Moderate Drought |
| Köppen Climate Classification | Dfb - Humid Continental Mild Summer, Wet All Year |